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Biomedical subjects

U Wiesmann

Publications and source records attributed to U Wiesmann.

At least 19 recordsLinked to original sources
PubMed2006

[On the stability and modifiability of the sense of coherence in active seniors].

According to Antonovsky, the sense of coherence (SOC) determines health and wellbeing. This life orientation is shaped up to the age of 30 and is supposed to remain constant up to senior age. In a field study, in which the SOC, psycho-social resources and subjective health were assessed at three points in time, it could be shown for the first time that the SOC in old age can be malleable and expanding. The master sample (time t(1)) consisted of N = 58 active and "healthy" seniors at the mean age of 66.3 years (65.5% female), who decided to take part in a 14-week program focusing on physical activity and/or self-reflection (endurance training, strength training, yoga, or meditation), respectively. One year before, 90% of them had participated in the Greifswald Aging Study (t0). The intervention study was attended regularly by n = 42 persons (t1 and t2). The SOC and associated health appraisals remained constant over a period of one year (t0-t1); re-test reliabilities varied from satisfactory to very good. Overall, the current SOC (t1) was more important than the past SOC (t0) in accounting for current well-being (t1). The intervention (t1-t2) revealed that the elderly's SOC was significantly strengthened-independently of the program they took part in. Correspondingly, participants' wellbeing, subjective health and psycho-social resources were enhanced. Taking part in a systematic, age-based and group-oriented program that encourages an active and productive every-day life brings about coherence-promoting and health-promoting life experiences in old age.

Adaptation, Psychological↗
PubMed2005

[The desire for a child in a socio-structural context].

In the EU, Germany is one of the countries showing the lowest birth rate and the highest childlessness rate. The desire for a child competes with a variety of life goals that are propagated as valuable in an achievement-centered society. Psychologically speaking, it can be conceived of as a complex and highly ambivalent conflict between options. In view of adverse societal conditions, women and men at a fertile age face the problems of arbitration and of action insecurity, both of which are associated with the delay of the desire for a child and with abandonment of offspring, respectively. In this article, the socio-structural conditions of the desire for a child and of childlessness are specified, referring to relevant representative surveys, and important steps for overcoming this crisis are suggested.

Birth Rate↗
PubMed2005

Potential of OUR and OTR measurements for identification of activated sludge removal processes in aerated basins.

In order to develop a process control scheme to reduce energy costs for aeration in activated sludge systems with biological P removal, pre-denitrification and nitrification stages, the spatial distribution of carbon oxidation and nitrification was evaluated over a long full-scale plug flow aeration basin using an externally measured specific oxygen uptake rate (sOUR) and in basin measurement of the actual specific oxygen transfer rate (sOTR) with off-gas testing as well as with the calculated oxygen demand from NH4-N concentrations (sOTR(N)). Using a simple static model, a gas phase balance on oxygen and carbon dioxide, sOTR(N) values were also calculated from off-gas testing. Comparison of sOTR(N) to sOTR and sOUR for carbon oxidation (sOUR(C)) to nitrification (sOUR(N)) at different loading conditions allowed the oxidation processes to be followed over the three zones of the aeration basin. As expected, the distribution depended on the dissolved oxygen concentration (DO) in the basin. However, the major change was in the C-oxidation rate and not the nitrification rate. At a low DO, and when NH4-N was present in the zone, the amount of oxygen transferred for nitrification was nearly the same, but the overall sOTR was lower. The externally measured sOUR was only useful when it was differentiated into sOUR(N) and sOUR(C). sOUR(N) could be used to predict the nitrification rate in the basin. With further refinement, the gas phase balance model has potential to be used to monitor the degree of nitrification over the basin length. This can be integrated into a control scheme to reduce aeration costs by adjusting the DO setpoint according to loading conditions in the

Aerobiosis↗
PubMed2004

[Motor competence and quality of life in elderly active persons].

Physical activity is a vital pre-condition for healthy aging and well-being. While the association between objective and subjective health in old age has extensively been investigated, the relationship between objective motor competence-the capability of mastering motor demands in everyday life adequately by using motor resources optimally-and subjective health-related quality of life has not been studied yet. In an interdisciplinary study, 168 active seniors (36 men) at the mean age of 67 (range: 59-89) underwent a test battery assessing motor resources and two objective domains of everyday life motor competence-"Perceiving and Reacting" and "Mastering Complex Situations". Subsequently, participants rated their mental, physical, social, functional health and life satisfaction by questionnaire. Motor competence domains were age-dependent; the strongest decrease was found for "Mastering Complex Situations". Only "Mastering Complex Situations" was predicted by motor resources: competent seniors in this domain were faster in motor activity, simple reactions, body movements following acoustic and optic signals, and showed a stronger handcraft and a higher mobility. Overall, health-related quality of life was contingent upon motor competence: physical and functional health and-to a lesser extent-mental health and life satisfaction showed a systematic but moderate relationship to both motor competence domains. The results emphasize the significance of age-compatible and everyday life-adjusted physical activity for the well-being of elderly persons. Even active elderly persons show deficits in motor competence and should be trained, taking into account individual resources and flaws.

Activities of Daily Living↗
PubMed2004

[Salutogenesis in old age].

In this contribution, the significance of the salutogenic model (Antonovsky) and its core concept-the sense of coherence-for research into "successful aging" is explicated on the background of a gerodynamic perspective (Schroots). Common to both approaches is the idea that the basic principle of life is based on imbalance, disease, and suffering (heterostasis). According to this pessimistic view, aging is considered as the individual time dimension on which these inevitable impairments in biological, behavioral, and social respects take place. The continuous increase in entropy (disorder) will finally result in the death of the organism. In the face of gerontological research showing variability and individual plasticity in aging processes-especially for the third age-, the salutogenic question is why some people generally become (very) old and stay healthy. According to the salutogenic model, the sense of coherence determines the (re-)production of order over the life span and mediates the relationship between resources/stressors and health outcome. Considering activity/disengagement theory and the selective optimization with compensation model as an example, the integrative potential of the salutogenic model is shown. Finally, the value of the salutogenic model for the fourth age is discussed. Healthy aging is one chance of human existence, but in no way a collective duty that should be imposed on the individual.

Adaptation, Physiological↗
PubMed2004

Influence of mass transfer and chemical reaction on ozonation of azo dyes.

Azo dyes can be only mineralised by chemical oxidation. In this paper the oxidation of Reactive Black 5 (RB 5) and Reactive Orange 96 (RO 96) with concentrations between 35 and 5,700 mgL(-1) (RB 5) and between 20 and 2,050 mgL(-1) (RO 96) was investigated in a lab-scale bubble column. The reactor was modelled for two cases, a completely mixed and a plug flow gas phase. The oxidation rate was influenced by mass transfer for all dye concentrations used. For low dye concentrations mass transfer alone was decisive for the reaction rate showing no enhancement due to chemical reaction, E approximately equal to 1. However, in the region of high dye concentrations, the slope of the ozone concentration profile inside the liquid boundary layer increases more and more with increasing dye concentration as a result of a chemical oxidation. Therefore, the enhancement factor depends on the type and concentration of the azo dyes. For RB 5, a diazo dye, an enhancement factor of E = 5.5 was observed for cd = 2,000 mgL(-1), RO 96, a mono azo dye, with a remarkably higher chemical oxidation rate shows an E = 16 for cd = 2,050 mgL(-1).

Azo Compounds↗
PubMed2004

A control strategy for reducing aeration costs during low loading periods.

The efficiency of the aeration system in a full-scale activated sludge basin with 3 separately controlled aeration zones was improved for the low loading period in summer. The air flow rate to each aeration zone is currently regulated to hold a preset dissolved oxygen concentration (DO). Four different DO setpoint combinations were tested, each one for a one week period, using dynamic off-gas testing to measure the standardised oxygen transfer efficiency (alphaSOTE). As the DO setpoints were lowered, the total air flow rate to the basin decreased initially. A low DO in the first zones slowed biomass activity and pushed the load towards the end of the aeration basin. The relationship between alphaSOTE and the specific diffuser flow rate qD is different for each zone. In Zone 1 there was a strong decrease in alphaSOTE as qD increased, while Zones 2 and 3 were fairly independent of qD, Zone 2 at a higher level than Zone 3. Aeration costs were reduced by 15% for the most efficient combination. To achieve even more savings, a control strategy adjusting oxygen transfer rates over the aeration basin to the necessary oxygen transfer rates is suggested. It is based on changing the DO setpoints to reach the lowest total air flow rate while meeting the effluent requirements.

Air↗
PubMed2003

[Validation of the German version of the Voice Handicap Index].

The voice handicap index (VHI) was developed in the United States for subjective evaluation of a voice disturbance by the patient. The translation into German has been applied for a German population of patients. It was validated by the examination of 316 adult patients, 221 female and 95 male. The reliability of the VHI rests on a high Cronbach's alpha (0.96). A factor analysis in order to structure the items yields four factors that can be interpreted as negative voice experience (factor 1-explaining 20.83% of the variance after rotation), lack of assertiveness (factor 2-18.82%), lack of vocal power (factor 3-12.84%), and negative emotionality (factor 4-11.01%). The mean VHI scores differ significantly from each other in different degrees of voice disturbance as estimated by the patients themselves. The voice handicap index is qualified as a diagnostic tool for German-speaking countries.

Adolescent↗
PubMed2003

Mechanism and kinetic model for the decolorization of the azo dye Reactive Black 5 by hydrogen peroxide and UV radiation.

A kinetic model for the decolorization of C.I. Reactive Black 5 by the combination of hydrogen peroxide and UV radiation was developed based on experimental results and known chemical and photochemical reactions. The observed kinetic reaction coefficient was determined and correlated as a function of hydrogen peroxide concentration and UV intensity. The validity of the rate expression was tested experimentally in a parameterization study. The decolorization rate follows pseudo-first order kinetics with respect to dye concentration. The rate increases linearly with UV intensity and nonlinearly with increasing hydrogen peroxide concentration, going from a linear relationship at low H(2)O(2) concentrations to a maximum as hydrogen peroxide concentration continues to increase. The decolorization rate expression derived from the proposed reaction mechanism was reconciled with that used for correlating the experimental data.

Azo Compounds↗
PubMed2002

Phosphorus removal with membrane filtration for surface water treatment.

Surface waters are often burdened with inflows of low quality water, so that drinking-water production, swimming or ground water charging must be restricted. To ensure the long-term use of such surface water it is necessary to treat the influents or the water used for ground water charging. The current treatment process for phosphorus and turbidity removal is a process combination called floc filtration. By using this conventional method it is possible to reduce the dissolved ortho-phosphate and the turbidity (particulate phosphorus) as well as the amounts of algae and pathogenic organisms to very low concentrations. The high degree of reduction is only achieved by a relatively high dosage of chemicals. A comparison will be made between this process, which represents the state-of-the-art, and the combination of precipitation/coagulation with micro-/ultrafiltration in dead-end filtration mode.

Filtration↗
PubMed2002

Comparison of the efficiency of large-scale ceramic and membrane aeration systems with the dynamic off-gas method.

The aeration systems of two full-scale activated sludge basins were compared over 2.5 years under the same operating conditions using dynamic off-gas testing. Only the material of the diffuser was different, membrane vs. ceramic tube diffusers. The experimental design took the complexity and dynamics of the system into consideration. The investigation has shown that, although the membrane diffusers have higher initial standard oxygen transfer efficiency (SOTE) and standard aeration efficiency (SAE), these decreased over time, while the SAE of the ceramic diffusers started lower, but increased slightly over the whole period. Measurement of air distribution in the basins along with dissolved oxygen concentration profiles have provided important information on improving process control and reducing energy costs. The results show that dynamic off-gas testing can effectively be used for monitoring the aeration system and to check design assumptions under operating conditions. The information can be used to improve the design of new aeration systems or in retro-fitting existing basins.

Ceramics↗
PubMed2001

Kinetics of decolorization and mineralization of the azo dye reactive black 5 by hydrogen peroxide and UV light.

C.I. Reactive Black 5 is one of the most used reactive dyes for textile finishing. It is a diazo dye, which can be decolorized by facultative anaerobic bacteria, sulfate reducing bacteria and aerobic white rot fungi. Mineralization by microorganisms has proven difficult. Advanced oxidation processes are promising alternatives for the decolorization and mineralization of Reactive Black 5, alone and in combination with aerobic biodegradation. The kinetics of the decolorization of Reactive Black 5 using a combination of hydrogen peroxide and UV radiation have been investigated. The rate of decolorization is first order with respect to dye concentration. It is enhanced with increasing hydrogen peroxide concentrations up to an optimum value. In our model we have correlated an empirical reaction rate expression which considers the contribution of both hydrogen peroxide and UV flux radiation based on the reaction kinetics. This empirical correlation agrees well with the experimental data for these conditions. Complete decolorization corresponded with 40-50% mineralization of the dye. Further mineralization can be achieved with extended radiation time.

Coloring Agents↗
PubMed1999

Microvesicular steatosis, hemosiderosis and rapid development of liver cirrhosis in a patient with Pearson's syndrome.

BACKGROUND/AIMS: Pearson's marrow-pancreas syndrome consists of refractory sideroblastic anemia with vacuolization of marrow precursors and exocrine pancreas dysfunction. Patients with this disease usually have large deletions of the mitochondrial genome. We report a patient with Pearson's syndrome who had predominantly hepatic manifestations such as microvesicular steatosis, hemosiderosis and rapidly developing cirrhosis. METHODS: Analysis of the mitochondrial and nuclear genomes, determination of enzyme activities and of the hepatic iron content were performed using standard techniques of molecular biology and biochemistry. RESULTS: The patient had typical ringed sideroblasts in a bone marrow smear and a 7436-bp deletion of the mitochondrial genome in all tissues investigated, compatible with Pearson's syndrome. He died within 3 months after birth due to liver failure. Histopathological analysis of the liver revealed complete cirrhosis with signs of chronic cholestasis, microvesicular steatosis and massive hemosiderosis. In addition, the patient was heterozygous for the C282Y and H63D mutations of the hemochromatosis gene. CONCLUSIONS: Pearson's syndrome should be added to the list of neonatal diseases which can cause microvesicular steatosis, hepatic accumulation of iron and liver cirrhosis.

Disease Progression↗
PubMed1999

Soluble IL-6 receptor induces calcium flux and selectively modulates chemokine expression in human dermal fibroblasts.

Truncated forms of cytokine receptors have been regarded as modulators of the activity of their cognate ligands. In addition to inhibiting effects of their respective ligands, soluble receptors can also facilitate ligand-mediated signaling. Several studies have demonstrated that exogenous IL-6 in association with the soluble IL-6 receptor alpha (sIL-6Ralpha) can activate cells expressing the gp130 signal transducer lacking the specific, membrane-bound IL-6Ralpha. Since cell cultures of human dermal fibroblasts express high amounts of IL-6, we examined whether the addition of sIL-6Ralpha in association with endogenous IL-6 would be sufficient to stimulate these cells via gp130. As an early rapid signal we analyzed changes in intracellular free calcium concentrations ([Ca2+]i). Addition of sIL-6Ralpha induced an acute and transient increase in cytosolic free calcium concentrations in a dose-dependent fashion. This Ca2+-signal was abolished when cells were pretreated with anti-IL-6 or anti-gp130 antibodies. Using flow cytometric analysis we could demonstrate membrane-associated IL-6 and gp130, but not IL-6Ralpha on fibroblasts. We also analyzed MCP-1 and IL-8 expression as a response involved in the more recently recognized chemoattractant functions of fibroblasts, and found MCP-1 to be up-regulated, but not IL-8. These data suggest that sIL-6Ralpha binds to cell-associated, endogenous IL-6 produced by fibroblasts and this complex then activates the cells via gp130. This pathway of fibroblast activation by sIL-6Ralpha adds another dimension to the role of fibroblasts in the cytokine network.

Antigens, CD↗
PubMed1997

Detection and characterization of mitochondrial DNA rearrangements in Pearson and Kearns-Sayre syndromes by long PCR.

We used a strategy based on long PCR (polymerase chain reaction) for detection and characterization of mitochondrial DNA (mtDNA) rearrangements in two patients with clinical signs suggesting Pearson syndrome and Kearns-Sayre syndrome (KSS), respectively, and one patient with myopathic symptoms of unidentified origin. Mitochondrial DNA rearrangements were detected by amplification of the complete mitochondrial genome (16.6 kb) using long PCR with primers located in essential regions of the mitochondrial genome and quantified by three-primer PCR. Long PCR with deletion-specific primers was used for identification and quantitative estimation of the different forms of rearranged molecules, such as deletions and duplications. We detected significant amounts of a common 7.4-kb deletion flanked by a 12-bp direct repeat in all tissues tested from the patient with Pearson syndrome. In skeletal muscle from the patient with clinical signs of KSS we found significant amounts of a novel 3.7-kb rearrangement flanked by a 4-bp inverted repeat that was present in the form of deletions as well as duplications. In the patient suffering from myopathic symptoms of unidentified origin we did not detect rearranged mtDNA in blood but found low levels of two rearranged mtDNA populations in skeletal muscle, a previously described 7-kb deletion flanked by a 7-bp direct repeat and a novel 6.6-kb deletion with no repeat. These two populations, however, were unlikely to be the cause of the myopathic symptoms as they were present at low levels (10-40 ppm). Using a strategy based on screening with long PCR we were able to detect and characterize high as well as low levels of mtDNA rearrangements in three patients.

Adolescent↗
PubMed1996

Determination of the activities of the enzyme complexes of the electron transport chain in human fibroblasts.

In order to improve the determination of the activities of the enzyme complexes of the electron transport chain (ETC) in fibroblasts, we characterized the isolation of mitochondria and measured enzyme activities in mitochondrial preparations from fibroblasts of control subjects and patients with suspected mitochondrial cytopathy. The isolation procedure yielded 54% of the citrate synthase activity in fibroblasts, with a 6-fold enrichment in this mitochondrial marker enzyme. The activities of the complexes of the ETC were linear with time and with the mitochondrial protein concentration used. The coefficients of variation for the enzyme activities determined were in the range of 10% in mitochondria from identical fibroblast cultures and between 30 and 70% in mitochondria from different fibroblast cultures of the same or of different patients. Decreased activities of one or more enzyme complexes (defined as an activity below the 95% confidence limit of control values) were found in 15 of 22 patients investigated. When compared with activities obtained in liver or skeletal muscle obtained at autopsy, the results were identical in three but different in two patients. The studies show that the activities of the enzyme complexes of the ETC can be determined reliably and reproducibly in mitochondria isolated from fibroblasts and that the results obtained are potentially useful for the diagnosis of mitochondrial cytopathies in patients with suggestive symptoms and signs.

Cells, Cultured↗
PubMed1996

Absolute quantification of the hepatic glycogen content in a patient with glycogen storage disease by 13C magnetic resonance spectroscopy.

Using natural-abundance 13C magnetic resonance spectroscopy (MRS) on a conventional whole-body system operating at 1.5 T, the absolute hepatic glycogen concentration was noninvasively determined in a patient with type Ia glycogen storage disease. Furthermore, to assess the reliability of glycogen determination, hepatic glycogen content was assessed after an overnight fasting period in 35 healthy volunteers divided into two groups, one with a carbohydrate-rich diet, the other without any particular dietary preparation. In the patient, the glycogen concentration was found to be 458 mM. In the healthy subjects, average glycogen concentrations were 229 +/- 34 mM (mean +/- standard deviation) and 257 +/- 31 mM for the group without and with dietary preparation, respectively. The 13C-MRS results are in agreement with those obtained by conventional liver biopsy. 13C MRS in natural abundance may thus serve as a straightforward, fast, and noninvasive tool for quantification of the liver glycogen content in patients.

Adult↗