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M Emmerich

Publications and source records attributed to M Emmerich.

14 recordsLinked to original sources
PubMed2001

Design of graph-based evolutionary algorithms: a case study for chemical process networks.

This paper describes the adaptation of evolutionary algorithms (EAs) to the structural optimization of chemical engineering plants, using rigorous process simulation combined with realistic costing procedures to calculate target function values. To represent chemical engineering plants, a network representation with typed vertices and variable structure will be introduced. For this representation, we introduce a technique on how to create problem specific search operators and apply them in stochastic optimization procedures. The applicability of the approach is demonstrated by a reference example. The design of the algorithms will be oriented at the systematic framework of metric-based evolutionary algorithms (MBEAs). MBEAs are a special class of evolutionary algorithms, fulfilling certain guidelines for the design of search operators, whose benefits have been proven in theory and practice. MBEAs rely upon a suitable definition of a metric on the search space. The definition of a metric for the graph representation will be one of the main issues discussed in this paper. Although this article deals with the problem domain of chemical plant optimization, the algorithmic design can be easily transferred to similar network optimization problems. A useful distance measure for variable dimensionality search spaces is suggested.

Algorithms↗
PubMed2000

[Semi-invasive cardiac output measurement using a combined transesophageal ultrasound device. Early experiences].

OBJECTIVE: Measurement of cardiac output (CO) with pulmonary artery catheter (PAC) is currently item of many discussions. We investigated the reliability of results using the noninvasive measurement of aortic blood flow (ABF) (combined Doppler- and M-Mode transesophageal ultrasound, Dynemo 3000, Sometec Inc, Paris, France). METHODS: In 75 patients during cardiac or major abdominal surgery we performed 313 simultaneous measurements of CO and ABF. RESULTS: Placement of ultrasound probe into correct position took less than 2 min. Quality and stability of ultrasound signals were good. The coefficient of correlation between ABF and CO was found to be 0.89 with CO = 0.97 x ABF + 1.1, Bland-Altman-Test positive. CONCLUSION: Results of ABF detected by combined Doppler- and M-Mode-Echography are comparable with results of CO obtained by PAC. Therefore we are convinced that this noninvasive method will find its place in clinical situations of compromised CO.

Abdomen↗
PubMed2000

(AC)23 [Z-2] polymorphism of the aldose reductase gene and fast progression of retinopathy in Chilean type 2 diabetics.

A recent case-control study suggests that the allele (AC)23 of a variable number tandem repeat (VNTR) associated to the aldose reductase (ALR2) gene could be related to early retinopathy in Type 2 diabetics. By means of a longitudinal-retrospective study, we aimed to seek for a relationship between the rate of progression of retinopathy and the (AC)23 allele of the VNTR associated to the ALR2 gene. A random sample was obtained of 27 Type 2 diabetics (aged 68.1 +/- 10.6 years, diabetes duration = 20.7 +/- 4.8 years, mean HbA1 = 10.6 +/- 1.6%). The mean HbA1 was the arithmetic average of 2.2 measurements per patient per year of total glycosilated hemoglobin (Gabbay method, normal range: 4.2-7.5%). Retinopathy was graded by an Ophthalmologist in a scale from zero to four score points. The genotype of the (AC), VNTR was determined by 32P-PCR plus sequenciation in a Perkin-Elmer laser device. The Mann-Whitney test and either chi2 or Fisher's exact test were used. A P < 0.05 was considered as statistically significant. The retinopathy progression rate (RPR, points x year(-1)) was calculated by dividing the increment of retinopathy score (delta Retinopathy Score, [points]), by the duration of the follow up [years]. The 12 diabetics having the (AC)23 allele had a mean RPR 8.9 times higher (0.40 +/- 0.61 points x year(-1)) than the 15 patients who had alleles other than (AC)23 (0.045 +/- 0.099 points x year(-1), P = 0.037). Both groups were similar with respect to: mean HbA1 (10.5 +/- 1.4 and 10.7 +/- 1.7%, P = 0.95), age at diagnosis (48.5 +/- 6.3 and 46.3 +/- 14.0 years, P = 0.81), diabetes' duration (21.3 +/- 4.7 and 20.2 +/- 4.9 years, P = 0.41) and serum creatinine (0.89 +/- 0.2 and 1.13 +/- 0.5 mg dl(-1), P = 0.35). We concluded that, in Type-2 diabetics having similar glycemic control, the (AC)23 allele of the VNTR associated to the ALR2 gene, is associated to a 8.9 times faster progression of retinopathy than in patients who have other alleles.

Age of Onset↗
PubMed1999

[Aldose reductase gene polymorphism and rate of appearance of retinopathy in non insulin dependent diabetics].

BACKGROUND: Recent studies suggest that polymorphisms associated to the aldose reductase gene could be related to early retinopathy in noninsulin dependent diabetics (NIDDM). There is also new interest on the genetic modulation of coagulation factors in relation to this complication. AIM: To look for a possible relationship between the rate of appearance of retinopathy and the genotype of (AC)n polymorphic marker associated to aldose reductase gene. PATIENTS AND METHODS: A random sample of 27 NIDDM, aged 68.1 +/- 10.6 years, with a mean diabetes duration of 20.7 +/- 4.8 years and a mean glycosilated hemoglobin of 10.6 +/- 1.6%, was studied. The genotype of the (AC)n, polymorphic marker associated to the 5' end of the aldose reductase (ALR2) gene was determined by 32P-PCR plus sequenciation. Mutations of the factor XIII-A gene were studied by single stranded conformational polymorphism, sequenciation and restriction fragment length polymorphism. RESULTS: Four patients lacked the (AC)24 and had a higher rate of appearance of retinopathy than patients with the (AC)24 allele (0.0167 and 0.0907 score points per year respectively, p = 0.047). Both groups had similar glycosilated hemoglobin (11.7 +/- 0.2 and 10.5 +/- 1.6% respectively). Factor XIII gene mutations were not related to the rate of appearance of retinopathy. CONCLUSIONS: Our data suggest that the absence of the (AC)24 allele of the (AC)n polymorphic marker associated to the 5' end of the aldose reductase gene, is associated to a five fold reduction of retinopathy appearance rate.

Age of Onset↗
PubMed1996

Intrapartum fetal atrial bigeminy--diagnostic and therapeutic role of the fetal scalp stimulation test.

Concern for fetal hypoxia often leads to cesarean delivery when persistent fetal bradycardia is identified. A fetus with premature atrial contractions had a prolonged second-stage heart rate of 80 beats/min. Intrapartum echocardiography and electronic fetal heart rate monitoring distinguished bradycardia caused by blocked atrial bigeminy from hypoxic bradycardia. The fetal scalp stimulation test documented normal acid-base balance and normalized the ventricular rate, avoiding cesarean delivery.

Adult↗
PubMed1992

[The marginal sealing of composite inlays with different cavity liners].

In this in-vitro study we investigated the sealing properties of composite inlays (EOS system) dependent on 8 different base materials. Using a dye-penetration test, the sealing was determined after mechanical and thermal cycling. A partially massive dye-penetration was detected in most cases when one of the following materials was used: a calciumsalicylate cement (Dycal), a combination of calciumsalicylate cement and a resin (Basic), a calcium hydroxide filled resin (Prisma VLC-Dycal), or a zinc phosphate cement (Harvard Cement). In contrast to this, we discovered a complete or almost complete sealing in most cases after application of chemically-cured glass ionomer cements (Ketac-Bond, Ketac-Bond Aplicap, Base-Line) or a light-cured glass ionomer cement (XR-Ionomer) as base materials. From these results it can be concluded that the choice of base materials has an influence on the marginal sealing of composite inlays after thermal and mechanical cycling. However, it is not possible to make a definitive statement on the suitability of these base materials under clinical conditions, because the results of dye-penetration tests have only limited clinical validity.

Color↗
PubMed1991

[Validation of electronic by conventional pain diaries].

A new type of electronic pain diary was validated in an open, randomized, crossover study. The main target variables were the comparison of the correctly realized pain assessment entries as well as the recording of the number of adverse events. Selected for the study were 20 patients, who were either hospitalized, partially-hospitalized or treated on an out-patient basis, with painful spondylogenic spinal syndrome or osteoarthritis of the trunk-proximal large joints. The patients were randomly-assigned to the two groups. The first group initially received the conventional diary and thereafter the electronic diary; the sequence was reversed for the second group. The drug therapy consisted of the NSAID, Ibuprofen, at an individually-adjusted dosage. Additional therapeutic measures were carried out by all the patients. The electronic pain diary proved to be equivalent to the conventional diary with regard to adherence of the pain assessment entry times. At a defined equivalence range of +/- 20%, the statistical comparison showed that the limits were never exceeded. The equivalence test of Anderson-Hauck showed a significance level of p less than 0.0001. The minimum equivalence range was +/- 2%. It therefore follows, that the conventional method of data recording can indeed be fully replaced by the electronic method. Comparing the individual data of the 16 patients, from whom entries with both the electronic as well as the conventional pain diaries were submitted, a clear tendency for increased entries on adverse events in the electronic diary (C.D. 6.4 +/- 10.5/E.D. 36.4 +/- 44.1) was demonstrated. No significant difference, however, was shown for the number of patients making data entries on adverse events in the electronic pain diary compared to those patients, who made their entries on adverse events in the conventional diary. According to the data from the physicians and patients, the Ibuprofen treatment results in an improvement in 90%/75% of cases, respectively. Likewise, the functional impairment of the affected joints as well as the swelling decreased markedly. The advantages of the electronic data recording system, i.e. closely-meshed controls can be carried out, transcriptional errors are minimized, data can be processed on-line, no possibility to subsequently change an entry, stand in contrast to the feature that there is no possibility to make free-style entries. The employment of the electronic system in the recording of individual data and subjective data represents a substantial improvement with regard to the quantity and quality of the data.

Adult↗
PubMed1989

CD20 positive human B lymphocytes separated with the magnetic cell sorter (MACS) can be induced to proliferation and antibody secretion in vitro.

A method is described for the efficient purification of human B lymphocytes from peripheral blood by magnetic separation. Biotinylated, superparamagnetic particles were coupled to target cells by fluorescein isothiocyanate conjugated avidin and biotinylated monoclonal antibodies directed against cell surface antigens. This combination permitted flow cytometric control of the magnetic separation. Ficoll-Paque-separated peripheral blood mononuclear cells were first eliminated from monocytes by leucine-methyl ester treatment. B cells were enriched to 97% after magnetic depletion of CD3-positive T cells and magnetic enrichment of CD20-positive B cells. The separated B cells could be induced to proliferation and antibody production by various in vitro stimuli.

Antibody-Producing Cells↗
PubMed1983

Ventricular volume and cognitive deficit: a computed tomographic study.

A group of 35 patients with presumptive diagnosis of Alzheimer disease and 29 normal volunteer spouse controls, all over the age of 60, underwent medical and neurologic evaluation, an extensive psychometric battery, and CT scanning. CT ventricular volume was derived for each CT section by algorithm summation of the number of pixels within a user-defined cerebrospinal fluid range. Composite ventricular volume for each patient, obtained by summation of the individual section ventricular volumes, was corrected for brain size by dividing by the sum of the five largest brain section volumes. For the normal group, composite ventricular volume thus derived was 5.2% and for the impaired group 7.5%; the 44% difference was significant (p less than .009). Increasing ventricular volume was significantly associated with increasing severity of cognitive impairment (p less than .05).

Aged↗
PubMed1982

The control of glucose 1,6-bisphosphatase by Ca2+ and calmodulin.

1. The control of glucose 1,6-bisphosphatase activity, the enzyme that degrades glucose 1,6-bisphosphate, a metabolite that regulates hexose phosphate metabolism, has been examined in a rat muscle extract. 2. The enzyme has been found to be activated by physiological Ca2+ concentrations. Ca2+ can be replaced by Sr2+ and Mn2+, but the effects are not so pronounced. 3. The Ca2+ effect is inhibited by EGTA. Trifluoperazine also inhibits enzyme activity. This effect can be reversed by adding exogenous calmodulin.

Animals↗
PubMedDate not supplied

Positron emission tomographic studies of aging and Alzheimer disease.

In this study the positron emission tomographic (PET)-18F-2-deoxy-2-fluoro-D-glucose (FDG) technique was used to study both normal aging and senile dementia. The results derived from 15 young normal subjects (mean age, 26 +/- 5 years) and 22 elderly normal subjects (mean age, 66 +/- 7 years) failed to indicate significant metabolic changes associated with age. A group of 24 patients with senile dementia (mean age, 73 +/- 7 years) showed consistent diminutions in regional glucose use relative to the elderly normals. Across all brain regions the diminutions were 17%-24%. There were also significant correlations between the measures of glucose use and the measures of cognitive functioning. Discriminant function classification analysis results indicate that better than 80% classification accuracy can be achieved for individual PET measures. These data suggest a possible future diagnostic use of PET in senile dementia.

Adult↗