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Biomedical subjects

R Lüthi

Publications and source records attributed to R Lüthi.

At least 19 recordsLinked to original sources
PubMed2003

Direct determination of the energy required to operate a single molecule switch.

Using a noncontact atomic-force and scanning-tunneling microscope in ultrahigh vacuum, we have measured the switching energy of a single molecule switch based on the rotation of a di-butyl-phenyl leg in a Cu-tetra-3,5 di-tertiary-butyl-phenyl porphyrin. The mechanics and intramolecular conformation of the switched leg is controlled by the tip apex of the noncontact atomic-force microscope. The comparison between experimental and calculated force curves shows that the rotation of the leg requires an energy less than 100 x 10(-21) J, which is 4 orders of magnitude lower than state-of-the-art transistors.

Journal Article↗
PubMed2002

Impact of teaching interventions on nurse compliance with hand disinfection.

The impact of teaching interventions and the availability of additional dispensers for alcoholic hand disinfection was measured during three study periods. A nursing care system of relevant nursing interventions was found to be a useful tool for the assessment of compliance with hand hygiene requirements if combined with an analysis of hand disinfectant use. This study shows that compliance with hand disinfection can be improved through targeted teaching and supportive structural improvements, and that this positive impact may persist even after targeted teaching activities have ended.

Guideline Adherence↗
PubMed2001

Factor V Leiden mutation in postthrombotic and non-postthrombotic venous ulcers.

OBJECTIVE: To determine the prevalence of the factor V Leiden mutation in patients with postthrombotic and non-postthrombotic venous ulcers. DESIGN: Case-control study. SETTING: Department of Dermatology, University Hospital of Zurich, Zurich, Switzerland. PARTICIPANTS: Seventy-three consecutive outpatients and inpatients with venous ulcers and 45 age- and sex-matched control subjects (matched to the 42 patients with postthrombotic syndrome). MAIN OUTCOME MEASURES: Frequency of postthrombotic and non-postthrombotic findings in patients with venous ulcers. Prevalence of the factor V Leiden mutation in these different subgroups. RESULTS: Postthrombotic syndrome was identified as the cause of 42 (58%; 95% confidence interval [CI], 45%-69%) of 73 venous ulcers, and the remainder were caused by primary valvular insufficiency. In postthrombotic ulcers, the prevalence of the factor V Leiden mutation was 38% (95% CI, 24%-54%) (16/42), which corresponds to an odds ratio of 13.2 (95% CI, 2.8-62.3; P<.001). In non-postthrombotic venous ulcers, the prevalence was 16% (95% CI, 5%-34%) (5/31), which corresponds to an odds ratio of 3.2 (95% CI, 1.0-10.0; P =.07). CONCLUSIONS: The factor V Leiden mutation is highly prevalent in patients with postthrombotic venous ulcers. Even patients with non-postthrombotic venous ulcers show a moderately elevated prevalence of the factor V Leiden mutation. Some of the latter might be misclassified because of near-to-perfect revascularization after asymptomatic deep venous thrombosis. However, as long as the therapeutic consequences of the factor V Leiden mutation are not established, systematic screening cannot be recommended in patients with venous ulcers.

Aged↗
PubMed1994

The significance of morphine concentrations in the cerebrospinal fluid in morphine caused deaths.

Morphine analysis was performed using a variety of immunoassay methods in blood, urine and the cisternal cerebrospinal fluid (CSF) from 23 patients dying opiate-related deaths. Of these, 16 were a result of intravenous morphine or heroin use. The blood and CSF morphine concentrations were determined using both fluorescence polarization immunoassay (FPIA) and radioimmunoassay (RIA), while urine was analyzed by enzyme multiplied immunoassay technique (EMIT). Urine morphine concentrations were greater than 0.300 microgram/mL in all but one case. Blood and CSF morphine concentrations were found to be poorly correlated, and it was concluded that one should not be used to predict the other. Following intravenous administration, CSF morphine concentrations of greater than 0.02 microgram/mL were however found to be consistent with death from morphine related respiratory depression. As intrathecal or epidural administration of morphine can greatly influence the CSF concentration without inducing respiratory depression, the site of collection of the CSF must be known, as must the route of administration in order to properly interpret CSF morphine concentrations.

Drug Overdose↗
PubMed1987

[The Berne Härz-As (Ace of Hearts) Project: goals, study plan and initial results].

The Berne Härz-As (Ace of Heart) project is a randomized trial in changing cardiovascular risk factors, morbidity and subjective health. It further investigates to what extent psychosocial and somatic factors account for these health indicators in the course of at least 4 years. A pilot study conducted in two companies (N = 620) indicates that the project is feasible and acceptable to both management and employees and that the intervention goals are justified.

Cardiovascular Diseases↗
PubMed1984

[Vasospastic syndrome in a young women with migraine, Raynaud's disease, cerebral ischemia and myocardial infarction].

The case is described of a 32-year-old female patient who has suffered since puberty from acute migraine attacks and Raynaud syndrome of both hands. In June 1981 acute posterior cerebral ischemia occurred. 11/2 years later the patient was hospitalized for acute myocardial infarction with normal and patent coronary arteries. Thereafter, the patient was treated with nifedipin and anticoagulation, and no other vascular complications have since occurred. The authors suggest that the patient is suffering from a diffuse vasospastic disorder leading to migraine attacks, Raynaud syndrome, cerebrovascular ischemia and myocardial infarction, in view of the fact that the patient has no other known risk factors for early vascular complications.

Adult↗
PubMed1982

[Preventive parent training: results in the cognitive area].

In an intervention study, parents were offered courses on interpersonal interaction and child education. The evaluation procedures are briefly described and results concerning two types of course contents (knowledge of definition of a technical term; familiarity with an educational concept) are presented. It appears that after 45 months, knowledge transmitted in the course is still present, although with a loss of differentiation, depending on practical relevance of the course materials.

Adult↗