Search PubMed⌕ Search

Biomedical subjects

L Kullmann

Publications and source records attributed to L Kullmann.

At least 19 recordsLinked to original sources
PubMed2002

Time-dependent cross-correlations between different stock returns: a directed network of influence.

We study the time-dependent cross-correlations of stock returns, i.e., we measure the correlation as the function of the time shift between pairs of stock return time series using tick-by-tick data. We find a weak but significant effect showing that in many cases the maximum correlation appears at nonzero time shift, indicating directions of influence between the companies. Due to the weakness of this effect and the shortness of the characteristic time (of the order of a few minutes), our findings are compatible with market efficiency. The interaction of companies defines a directed network of influence.

Journal Article↗
PubMed2001

Preferential growth: exact solution of the time-dependent distributions.

We consider a preferential growth model where particles are added one by one to the system consisting of clusters of particles. A new particle can either form a new cluster (with probability q) or join an already existing cluster with a probability proportional to the size thereof. We calculate exactly the probability Pi(k,t) that the size of the ith cluster at time t is k. We analyze the asymptotics, the scaling properties of the size distribution and of the mean size, as well as the relation of our system to recent network models.

Journal Article↗
PubMed1999

[Hungarian adaptation of the WHO method for measuring quality of life].

Authors explain the importance of quality of life assessments starting from the health definition of the World Health Organization. They review the basic possibilities of quality of life assessments. They shortly introduce the quality of life instrument developed by the World Health Organization, the WHOQOL. They report on the Hungarian adaptation procedure. Finally they point out the strengths and weaknesses of the method and review the possible territories of its use, e.g. the medical practice, the improvement of the communication between patient and physician, the accreditation, the research and the influencing of health policy.

Humans↗
PubMed1999

Lower limb amputations during 3 years in Hungary.

We reviewed nationwide hospital data of amputations during 3 years to provide a comparison with similar data gathered about 20 years ago. Data were provided by the National Medical Records Centre and processed by our personally developed programmes. The cause of amputation was most often vascular disease, amputees were usually elderly, and the large majority of amputation surgery was carried out on the lower limb. The rate of transtibial amputation has increased favourably in the last 2 decades, but there are large regional differences within the country. Mortality parameters remarkably exceed those of foreign countries. Although the data accuracy is compromised, there are still ways of exploiting the data in favour of quality improvement of care, e.g. improve transtibial amputation rate, reduce mortality. The publication of data can be of benchmarking importance for hospitals by enabling them to compare their own results with those of other hospitals, as well as to develop and improve performance.

Adult↗
PubMed1997

[2-year results of leg amputation in Hungary based on a nationwide data base].

Authors review nation-wide hospital data of amputees over two years in order to make comparison with similar data gathered about 20 years ago. Data were provided by the National Medical Records Centre and processed by own developed programmes. The quality level of data validity is slightly criticised. The cause of amputation was most often vascular disease, amputees were elderly and large majority of amputation surgery was carried out on the lower limb. The rate of below-knee amputation has gone up favourably over the 20 years, but there are large regional differences within the country. Mortality parameters remarkably exceed those of foreign countries. Regarding compromised data accuracy, still there are ways of exploiting data in favour of quality improvement of care, e.g. improve below-knee amputation rate, reduce mortality. Publication of data can be of bench-marking importance for hospitals by enabling them to compare own results with those of other hospitals, as well as develop and improve performance.

Amputation, Surgical↗
PubMed1994

[Observations on real drug need of hospitals].

Authors indicate that a considerable share of the inpatient drug supply "gets out" of the institution, another remarkable share is administrated to patients due to polypragmasia. Consequently, in-patient drug-costs might be reduced by large amounts without jeopardizing the quality of care. Authors made attempts to measure the first of the two mentioned losses by repeated systematic observation of patients' clinical charts, while the second one was assessed by several peer-reviews. Illegal drug losses were tackled by involving an external ordinary drugstore, to deliver hospital staff members prescription drugs, while polypragmasia was successfully reduced by introducing changes derived from reports of peer-reviews, over the past three years. Additionally, since the most costly group of drugs is that of the antibiotics, an internal treatment protocol system was set up based on collective knowledge and consensus of all doctors. Authors recommend that once all listed management activities are introduced and conducted in a hospital, department-specific daily drug-cost rationing can be created fairly based on the average drug consumption of the respective department.

Drug Costs↗
PubMed1991

[Results of amputation and rehabilitation].

Authors report on a questionnaire study of amputees having been rehabilitated in three departments of the National Institute of Medical Rehabilitation in 1988. The study was conducted one and a half years (average) after amputation. In comparison to an earlier study on a similar population the ratio of distal amputations has increased and the prosthetic fitting has improved. From these points results are well comparable with international standards. The feeling of isolation of the amputees has decreased since the earlier study. Their chance to get a job has deteriorated essentially, their subsistence problems have increased.

Adolescent↗
PubMed1989

[Treatment and rehabilitation of dysmelic children].

It is reasonable to make the plan of treatment and rehabilitation of dysmelic children in infancy and to realize it after an agreement with the parents, if possible in a care system. A careful operative indication considering the possibilities of orthetic-prothetic supply from every respect is necessary. The supply of the orthopaedic apparatus is generally individually planned and it succeeds only rarely to use standard prosthesis and orthesis. It is worthwhile to strive that the rehabilitation procedure should enable the child to go to the general school in the usual time. Based on the presentation of a few cases the author describes the ground principles of treatment-rehabilitation summarized in the paper.

Artificial Limbs↗
PubMed1987

Hip disarticulation in peripheral vascular disease.

The authors had to perform hip disarticulation on vascular patients in an increasing number - in spite of the general amputation principles. In the majority of the cases hip disarticulation followed other, more distal amputations of the same lower limb. Results of wound-healing, prosthetic fitting and mortality are poor, nevertheless this operation may lengthen life, relieve pain and lead to a tolerable life, usually bound to wheel-chair.

Adult↗
PubMed1987

Rehabilitation of hemiplegic amputees.

The authors report on results of rehabilitation of their 49 hemiplegic amputee cases. Most of the patients had vascular disease. A majority of them had also other conditions with negative effects on rehabilitation. 29 patients achieved walking, 14 used a wheelchair, three remained bedridden and another three died during the hospitalization. The influence of different factors on mobility has been studied. Below-knee amputation had significant effect on mobility, and the time interval between amputation and hemiplegia was also of importance. Other correlations need further studies and more experience.

Activities of Daily Living↗
PubMed1987

Evaluation of disability and of results of rehabilitation with the use of the Barthel index and Russek's classification.

At a rehabilitation medicine unit for mainly vascular lower-limb amputees the use of simple and comparable methods of evaluation of gait performance (Russek's classification) and activities of daily living (the Barthel index) have been studied. Results of the two methods correlate and both have prognostic value concerning rehabilitation outcome.

Activities of Daily Living↗