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At least 253 records · Page 14Linked to original sources
PubMed2000

Calibration of the National Institute of Standards and Technology tritiated-water standards

Massic activity values obtained for NBS/NIST tritiated water SRMs 4927 and 4927E, using internal gas-proportional counting, are reported. The massic activity ratios of all of the available NBS/NIST tritiated water SRMs and samples of the Level 1 and Level 3 tritiated water standards produced by the National Physical Laboratory (NPL) in 1996 were measured using an extensive series of liquid-scintillation intercomparisons. New massic activity values obtained for the NPL standards, using the gas counting results for SRM 4927E and the results of the liquid-scintillation intercomparison, are also reported. A new determination of the half-life of tritium was made using massic activity data for SRM 4927 over a period of 38 years. The new value is (4504+/-9) (one standard deviation) days. This value differs significantly from the previous NBS/NIST value but is in good agreement with the value recommended in the Evaluated Nuclear Structure Data File (ENSDF).

Journal Article↗
PubMed2005

A randomized controlled trial of the use of self-help materials in addition to standard general practice treatment of depression compared to standard treatment alone.

BACKGROUND: The purpose of the study was to examine whether the addition of a brief individual self-help package to standard primary-care treatment of depression with antidepressants is associated with any additional improvements in clinical outcome. METHOD: Individuals with major depressive disorder who were prescribed an antidepressant were recruited through their general practitioner (GP) and allocated randomly to standard treatment alone or standard treatment plus self-help. Assessments of symptoms, social adjustment, global functioning, satisfaction with treatment and knowledge about the management of the disorder were completed at three time points over 26 weeks. RESULTS: One hundred and twelve individuals agreed to participate and 96 met criteria for inclusion in the randomized controlled trial. Subjects in both treatment conditions improved substantially over the study period; the mean Beck Depression Inventory (BDI) score fell from 27.3 to 13.9 in the intention-to-treat analysis. There were no between group differences in outcome on any of the primary outcome measures, nor did these approach even marginal significance. Patients and GPs were highly satisfied with the self-help programme, and the intervention as compared to the control group reported significantly greater improvements in knowledge about depression and satisfaction with information received about depression. CONCLUSIONS: An individualized self-help package improved perceived knowledge about depression but did not have identifiable effects on outcome when offered to patients treated in primary care. The study was sufficiently well powered to detect relatively small effects.

Adolescent↗
PubMed2001

A comparison of liquid hydrocarbon calibration standards in piston cylinders and standard cylinders with eductor tubes.

Natural gas liquid standards consist of various components primarily in the C1-C6 range; they are available in three types of cylinder packages: piston cylinders and two other types of standard cylinders with eductor tubes. The three cylinder packages have different operation conditions and thus a sample may behave differently in each of the packages. The piston cylinder maintains the components in a single liquid phase at a constant pressure, while the standard cylinders maintain the components as a two-phase mixture. Typically, the components may distribute between the two phases in different concentrations depending on the various thermodynamic variables, such as temperature, pressure, and volume. This study will examine the integrity of the sample in the three cylinder packages during a controlled cylinder depletion. The results for the various cylinders will be compared with a theoretical model of the experiments.

Journal Article↗
PubMed1989

CORGEN: a FORTRAN-77 generator of standard and non-standard DNA helices from the sequence.

An analytical procedure CORGEN generates a variety of DNA double-stranded structures from user-supplied sequence using a nucleic acid database incorporated into a standard FORTRAN-77 program. Alternatively, the cylindrical polar coordinates of DNA components may be supplied from the external table. An algorithm that performs intercalation sites in DNA is described. This procedure can be used to generate complexes of antibiotics with DNA. Non-standard DNA structures can be built by alternating the global helical twist and global helical rise in the regular DNA helix. The procedures described can be used for computer generation of a variety of non-standard DNA structures which can be subjected to molecular mechanics and dynamics simulations.

Base Sequence↗
PubMed1990

Why the standard view is standard: people, not machines, understand patients' problems.

The 'Standard View' regarding computer-based medical diagnostic decision support programs is that, while such systems may be useful adjuncts to human decision-making, they cannot replace human diagnosticians. Mazoué (1990) disputes this viewpoint. He notes that human diagnosis is prone to a variety of errors, and claims that the processes of data collection for diagnosis and the intellectual task of making a diagnosis are independent. Mazoué believes that recent progress in computer-based diagnosis has been encouraging enough to consider the concept of "human-assisted computer diagnosis". This commentary explains why the Standard View should remain standard. Diagnosis is a complex process more involved than producing a nosological label for a set of patient descriptors. Efficient and ethical diagnostic evaluation requires a broad knowledge of people and of disease states. The state of the art in computer-based medical diagnosis does not support the optimistic claim that people can now be replaced by more reliable diagnostic programs.

Attitude to Computers↗
PubMedDate not supplied

Technical standards and guidelines: venous thromboembolism (Factor V Leiden and prothrombin 20210G >A testing): a disease-specific supplement to the standards and guidelines for clinical genetics laboratories.

These standards and guidelines are designed primarily as an educational resource for clinical laboratory geneticists to help them provide quality clinical laboratory genetic services. Adherence to this statement does not necessarily ensure a successful medical outcome. These standards and guidelines should not be considered inclusive of all proper procedures and tests or exclusive of other procedures and tests that are reasonably directed to obtaining the same results. In determining the propriety of any specific procedure or test, the clinical molecular geneticist should apply his or her own professional judgment to the specific clinical circumstances presented by the individual patient or specimen. It may be prudent, however, to document in the laboratory record the rationale for any significant deviation from these standards and guidelines.

Factor V↗
PubMed2003

Draft 16 of a working document for a proposed standard to be entitled: IEEE standard definitions of terms associated with ferroelectric and related materials.

Prior to acceptance of a standard by IEEE, it is important that the document be widely reviewed by experts in the field. This draft version of the standard is being published here to solicit that input. Readers are encouraged to submit any suggestions or corrections to the IEEE ferroelectrics standards committee for inclusion in the final version.

Journal Article↗
PubMed2001

Standards and guidelines for biopolymers in tissue-engineered medical products: ASTM alginate and chitosan standard guides. American Society for Testing and Materials.

The American Society for Testing and Materials (ASTM) is making a concerted effort to establish standards and guidelines for the entire field of tissue-engineered medical products (TEMPS). Safety, consistency, and functionality of biomaterials used as matrices, scaffolds, and immobilizing agents in TEMPS are a concern. Therefore, the ASTM has established a number of task groups to produce standards and guidelines for such biomaterials. Alginate is a naturally occurring biomaterial used for immobilizing living cells to form an artificial organ, such as encapsulated pancreatic islets. In order to aid in successful clinical applications and to help expedite regulatory approval, the alginate used must be fully documented. The ASTM alginate guide gives information on selection of testing methodologies and safety criteria. Critical parameters such as monomer content, molecular weight, and viscosity, in addition to more general parameters, such as dry matter content, heavy metal content, bioburden, and endotoxin content are described in the ASTM document. In a like manner, the characterization parameters for chitosan, a bioadhesive polycationic polysaccharide, are described in a separate guide. For chitosan, the degree of deacetylation is of critical importance. Control of protein content and, hence, potential for hypersensitivity, endotoxin content, and total bioburden are important in chitosan preparations for TEMPS. Together these two guides represent part of the effort on behalf of the ASTM and other interested parties to ensure quality and standardization in TEMPS.

Alginates↗
PubMed2006

Increase in linkage information by stratification of pedigree data into gold-standard and standard diagnoses: application to the NIMH Alzheimer Disease Genetics Initiative Dataset.

Patients diagnosed with a standard clinical method (subject to misclassification error) are often combined with patients diagnosed with a gold-standard method (with zero or very small misclassification error) in family-based studies of complex disease. For example, non-autopsied patients (NAP) are often included along with autopsy-proven (AP) patients in family-based studies of complex diseases, such as Alzheimer's disease (AD). Theoretical and simulation studies suggest that certain misclassification errors can result in severe reduction of power in genetic linkage and association analyses and that phenotype (or diagnostic) error can produce misleading results. Morton's test for heterogeneity can identify genomic regions where error may have led to loss in power. We applied this test to pedigree data from the NIMH Alzheimer's Disease Genetics Initiative Database separated into AP and NAP pedigrees. Morton's test identified one highly significant region of heterogeneity on chromosome 2. The source of the heterogeneity was due to significant indication of linkage in the AP pedigrees at position 109 cM (p value = 6.68 x 10(-5)) with no indication in the NAP pedigrees. Furthermore, Morton's test showed no evidence for heterogeneity on chromosome 19 in early-onset pedigrees that showed highly significant evidence for linkage in other published reports. These results suggest that supplementing linkage analysis with Morton's test can be usefully applied to genetic data sets that have AP and NAP samples, or other sample mixtures that include a 'gold standard' subgroup with reduced error rate, to increase power to detect linkage in the presence of diagnostic misclassification.

Alzheimer Disease↗
PubMed1977

Standardized karyotype of deer mice, Peromyscus (Rodentia). The Committee for Standardization of Chromosomes of Peromyscus.

A standard G-band karyotype is proposed for the genus Peromyscus. G-banded chromosomes of Peromyscus boylii glasselli (NF=56), numbered and arranged according to euchromatic lengths, serve as the standard. It is suggested that rearrangements of the standard pattern which occur in other species of Peromyscus be described using the general methods of the PARIS CONFERENCE (1971).

Animals↗
PubMedDate not supplied

Quantification of standards for length-of-stay based upon optimal patient care and standard medical practice.

Length-of-stay criteria are being developed by the Allegheny Professional Standards Review Organization (APSRO) in western Pennsylvania. In order to statistically document the standard of practice at the Eye and Ear Hospital of Pittsburgh, a retrospective review of patients who underwent laryngectomy with or without radical neck dissection was performed. Results demonstrated that routinely allowing only one day preoperative assessment deviates significantly from optimal medical practice and may place some patients at increased risk, especially for postoperative complications. From a cost-effective health care delivery point of view, abbreviated preoperative preparation contributes negatively to postoperative length-of-stay which was the most costly component of hospital health care for this group of patients. The development of appropriate standards of medical practice criteria using preexisting HEW mechanisms and scientifically designed prospective studies should be encouraged.

Age Factors↗
PubMed1989

The International Standard for Pituitary FSH: collaborative study of the Standard and of four other purified human FSH preparations of differing molecular composition by bioassays, receptor assays and different immunoassay systems.

The International Standard for Pituitary FSH (IS; in ampoules coded 83/575) was assayed in terms of the Second International Reference Preparation of Human Pituitary FSH and LH for Bioassay (IRP 78/549) by 27 laboratories in 13 countries using bioassays, receptor assays and immunoassays. Estimates of the FSH content of the IS by in-vivo bioassay were homogeneous both within and between laboratories and gave a combined geometric mean (with 95% fiducial limits) of 79.9 (74.6-85.4) i.u./ampoule. Estimates by different in-vitro bioassays and receptor assays were also homogeneous between assays and laboratories, and gave a combined geometric mean (with 95% fiducial limits) of 31.2 (28.8-33.9) i.u./ampoule. However, estimates by the 19 different immunoassay systems were heterogeneous and varied between 5 and 31 i.u./ampoule. The material in ampoules coded 83/575 was established by the World Health Organization as the International Standard for Pituitary FSH. It was assigned a unitage of 80 i.u./ampoule on the basis of its calibration by in-vivo bioassay, because this assay best identifies and defines the hormone. However, the introduction of the new IS will necessitate the recalibration of immunoassay kits. FSH 84/530, prepared in the same way as the IS from the same FSH preparation, did not differ significantly from the IS in any of the assay systems studied and appeared to be equally suitable as a standard. Four highly purified preparations of human FSH (FSH A-D), differing in their isoform compositions and in their in-vivo: in-vitro bioactivity ratios, were also studied.(ABSTRACT TRUNCATED AT 250 WORDS)

Biological Assay↗
PubMed1998

FDA Modernization Act of 1997: modifications to the list of recognized standards; availability; withdrawal of draft guidance "Use of IEC 60601 standards; medical electrical equipment"--FDA. Notice.

The Food and Drug Administration (FDA) is announcing the publication of the modifications to the list of standards that will be recognized for use in the premarket review process and withdrawing its draft guidance entitled "Use of IEC 60601 Standards; Medical Electrical Equipment." This will assist manufacturers who elect to declare conformity with consensus standards to meet all or part of medical device review requirements.

Device Approval↗
PubMed1991

[d-Camphor Reference Standard (Control 901) and dl-Camphor Reference Standard (Control 901) of National Institute of Hygienic Sciences].

The raw materials of d-camphor and dl-camphor were examined for the preparation of the "d-Camphor Reference Standard" and "dl-Camphor Reference Standard". Analytical data obtained were as follows: ultraviolet spectrum, lambda max = 257 nm; absorbance, E1%1cm(257 nm) = 723; infrared spectrum, 2956, 1742, 1045 cm-1; optical rotation, [alpha]20D = +42.9 degrees (d-camphor), [alpha]20D = -0.00 degrees (dl-camphor); melting point, 180 degrees C (d-camphor), 179 degrees C (dl-camphor); gas-chromatography, one impurity was detected in d-camphor and four impurities were detected in dl-camphor. Based on the above results, these raw materials were authorized to be the Reference Standards of the National Institute of Hygienic Sciences.

Camphor↗
PubMed1992

[d-Camphor reference standard (Control 911) and dl-Camphor Reference Standard (Control 911) of the National Institute of Hygienic Sciences].

The raw materials of d-camphor and dl-camphor were examined for preparation of the "d-Camphor Reference Standard" and "dl-Camphor Reference Standard". Analytical data obtained were as follows: ultraviolet spectrum, lambda max = 290nm; infrared spectrum, 2958, 1742, 1045cm-1; optical rotation, [alpha]D20 = +42.7 degrees (d-camphor), [alpha]D20 = -0.3 degrees (dl-camphor); melting point, 180 degrees C (d-camphor), 179 degrees C (dl-camphor); gas-chromatography (GC), one impurity was detected in d-camphor and three impurities in dl-camphor; assay, 99.5% (d-camphor), 99.5% (dl-camphor) by GC. Based on the above results, these raw materials were authorized as the Japanese Pharmacopoeia Standard (Control 911).

Camphor↗
PubMedDate not supplied

Evaluation of the International Organization for Standardization-International Dairy Federation (ISO-IDF) draft standard method for detection of Enterobacter sakazakii in powdered infant food formulas.

As a result of the growing recognition of Enterobacter sakazakii as an emergent pathogen, the International Dairy Federation (IDF) and the International Organization for Standardization (ISO) have standardized a reference method for the detection of E. sakazakii in milk powder products and powdered infant food formulas (IFF). The objectives of this study were to assess the applicability of the ISO-IDF draft standard, and to compare several chromogenic selective media for E. sakazakii [ready-to-use ESIATM, homemade E. sakazakii isolation agar, and Druggan-Forsythe-lversen (DFI) agar], and a selective media for Enterobacteriaceae Violet Red Bile Glucose (VRBG). We found that the method is sensitive, selective, and applicable to the analysis of powdered IFF, provided that some modifications are added. In particular, definition of typical colonies on chromogenic media should be less restrictive, and the possibility of using chromogenic media other than ESIA should be introduced. Any of the chromogenic media tested here could be used initially, since their performances were similar. In these media, alpha-glucosidase-positive but non-yellow-pigmented isolates should be also considered. Consequently, the yellow pigmentation test should be abandoned, or completed with another test in order to select colonies to confirm. Although the specificity of VRBG was relatively poor, it could be used as a second nonchromogenic medium.

Bacteriological Techniques↗
PubMed1994

[Quality assurance in nursing: nursing standard. Nausea, gagging and vomiting during emetogenic cytostatic therapies. Report of research into the development and introduction of nursing standards].

This report documents the introduction of standard-setting in the haemato-oncological reverse-isolation unit of the Kanton hospital, Basle. The topic is the prevention or reduction of nausea, choking and vomiting, and the treatment of patients who are receiving prolonged chemotherapy. The objective was quality assurance in nursing care. The definition of the desired outcome was the well-being and safety of patients. In addition the wish of the staff to increase their security in dealing with antiemetics was taken into consideration. The authors describe the basic problems they encountered in their strategies and actions for standard setting. By extensive use of measurement and evaluation it was possible, in cooperation with medical leadership, to develop instructional leaflets and checklists. Approximation to the intended outcome was achieved. The well being of patients and satisfaction of the safety-needs of staff and patients reached a high level. The report shows that the introduction of nursing standards requires great effort and a high level of commitment of the entire team. It also shows that the effort is worthwhile for patients and staff.

Antineoplastic Agents↗
PubMed1997

[Definition and evaluation of a documentation standard for intensive care medicine: the ASDI(Working Group for Standardization of a documentation system for Intensive care medicine) pilot project].

OBJECTIVES: A comparison of data from different intensive care units (ICUs) needs standardized documentation. In this study the ASDI documentation standard for intensive care was tested in clinical practice. Goal of the study was to evaluate parameters and functionality required for a national, interdisciplinary documentation system for intensive care. DESIGN: 13 ICUs participated in a 4-week trial using the provided program for documentation of all admitted patients during the observation period. In addition, a questionnaire was distributed to the unit coordinators. RESULTS: 376 patients were documented in 1591 patient days. Valid SAPS II scores were found in only 29% of the discharged patients (39.1 +/- 15.5 points). Time needed for data entry exceeded preset limits (ten minutes per patient and day) in 38% of the cases. All participants affirmed the necessity of a documentation standard for intensive care, giving quality control and cost analysis as the most important reasons. CONCLUSION: The ASDI data set fitted existing needs very closely. Only 7 out of 122 parameters (5.7%) were found to be superfluous and thus removed. Measures to reduce documentation effort to the default limits were a) a new, date orientated concept for manual recording, b) rede-sign of the user interface with new, user friendly data entry possibilities, and c) the integration of statistical analysis and reports in the documentation system. The revised data set represents a broad-based consensus, which seems to be well-suited as foundation for the national quality assurance program.

Adolescent↗