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Biomedical subjects

R Schoenberg

Publications and source records attributed to R Schoenberg.

8 recordsLinked to original sources

Simplified method for the determination of Ru, Pd, Re, Os, Ir and Pt in chromitites and other geological materials by isotope dilution ICP-MS and acid digestion.

A method for the determination of low Ru, Pd, Re, Os, Ir and Pt abundances in geological reference materials by isotope dilution inductively coupled plasma mass spectrometry (ICP-MS) after acid digestion in a high pressure asher (HPA-S) is presented. The digestion technique is similar to that using Carius tubes but easier to handle and reaches higher temperatures. Osmium can be determined as OsO4 with ICP-MS directly after digestion through a sparging technique. The remaining elements are preconcentrated by means of anion column chromatography. The resin is digested directly without elution leading to high yields but this causes problems if Zr is present at higher levels in the silicate rich materials. The analytical results for international platinum group element (PGE) reference materials, chromitite CHR-Bkg, basalt TDB-1 and gabbro WGB-1, are presented and compared with literature data, demonstrating the validity of the described method. Although higher in concentration, PGEs determined for reference material WGB-1 were worse than for TDB-1 indicating a more inhomogeneous distribution of the platinum group mineral phases. The low PGE abundance chromitite standard, CHR-Bkg, is likely to be homogeneous for Ru, Re, Os and Ir and is recommended as a reference material for the study of chromitites. Detection limits (3s x total procedure blank) range from 0.012 ng (Re and Os) to 0.77 ng (Pt), which could be further improved by applying higher quality acids.

Journal Article↗

Weaving the Web into legacy information systems.

For many years, client-server systems were developed as the backbone of clinical computing in leading hospitals around the country. Beth Israel Deaconess Medical Center now faces the challenge of bridging the technology gap between such systems and the Internet. While developing Web interfaces to legacy clinical systems gives a taste of the future, it is clear that complete institutional migration to the Web is not imminent. Asking clinicians to utilize two different systems, Web-based and legacy, in the interim phase is just one of the difficulties in such transition. This paper describes "Mbridge", a solution that allows legacy system users to exploit the benefits of the Internet in a fashion that does not interfere with their workflow and is both simple and affordable to implement. The service allows clinicians to work on the legacy platform while context-sensitive clinical content is streamed to the browser without their intervention. Using the system, we can gradually expose clinicians to new Web-based applications and resources without forcing them to operate two computing environments simultaneously. The service achieves these goals by means of linkage and coordination rather than by code-translation, data exchange or replication.

Computer Systems↗

Studying clinician-computer interaction in Web-based systems.

A growing of health-care organizations are in the process of modifying their clinical information systems (CIS) to support browser-based access. Consequently, care-providers are expected to modify their workflow to take advantage of the new technology. Intuitive interfaces, fast response and new functionality are few of the features used to promote endorsement of the change. In parallel, administrators are required to constantly assess user compliance and intervene where necessary to prevent rejection. Such monitoring translates to frequent surveys, analysis of logs and prudent utilization of user-groups. These methods tend to further burden users, suffer from "post-hoc" temporality and are difficult to maintain. In this paper we suggest an alternative approach to such data acquisition. "CareQuest" is an interactive Web-based service that can be woven into clinical applications without coding. It acquires information from the clinician at the relevant point in her workflow. It allows extensive interaction customization, data-driven response, real-time Web-based data-analysis, and full Web-based administration.

Evaluation Studies as Topic↗

Making ICU alarms meaningful: a comparison of traditional vs. trend-based algorithms.

Much of the work in the ICU revolves around information that is recorded by electronic devices. Such devices typically incorporate simple alarm functions that trigger when a value exceeds predefined limits. Depending on the parameter followed, these "boundary based" alarms tend to produce vast numbers of false alarms. Some are the result of false reading and some the result of true but clinically insignificant readings. We present a computerized module that analyzes real-time data from multiple monitoring devices using a customizable logic engine. The module was tested on 6 intensive care unit patients over 5 days, running alarm algorithms for heart rate, systolic and diastolic blood pressure as well as arterial oxygen saturation. Results show a ten-fold increase in positive predictive value of alarms from 3% using monitor alarms to 32% using the module. The module's overall sensitivity was 82%, failing to detect 18% of significant alarms as defined by the ICU staff. The results suggests that implementation of such methodology may assist in filtering false and insignificant alarms in the ICU setting.

Algorithms↗

Statistical issues for research on social drinkers.

The crucial problem in alcohol research is the large amount of inherently uncontrolled variation in the dependent variables. Because randomization with respect to key independent variables is frequently impractical or impossible, quasi-experimental and survey methods are being used to control residual variation statistically. For various reasons, however, the methods have often not been properly applied in alcohol research, endangering the replicability of true findings and prolonging the life of false claims. Ill-advised practices found in alcohol research that are discussed here are the use of partial correlations and standardized regression coefficients, of categorization or truncation of independent variables, and of available or convenient samples. It is recommended that researchers use unstandardized regression models, avoid categorizing independent variables, and scale them either to agreed on units of measure or use natural units (e.g., ounces or deciliters of alcohol consumed per occasion), and employ randomization or random sampling.

Adult↗

Alcohol use and cognitive loss among employed men and women.

A representative sample of 1,367 employed men and women in Detroit responded to questions about their drinking practices and then completed a cognitive test which measures abstraction abilities. Abstraction, tested while respondents were sober, decreased significantly as reported quantity of alcohol usually consumed per drinking occasion increased. (Am J Public Health 1983; 73:521-526.)

Adolescent↗