Comparison of the Electronic Structures and Energetics of Ferroelectric LiNbO3 and LiTaO3

This paper explains the origin of the ferroelectric instability in LiNbO3 and LiTaO3 and compares the electronic structures and energetics of the two materials.Comment: 31 pages, 11 Postscript figure

Gut microbiota functions: metabolism of nutrients and other food components

The diverse microbial community that inhabits the human gut has an extensive metabolic repertoire that is distinct from, but complements the activity of mammalian enzymes in the liver and gut mucosa and includes functions essential for host digestion. As such, the gut microbiota is a key factor in shaping the biochemical profile of the diet and, therefore, its impact on host health and disease. The important role that the gut microbiota appears to play in human metabolism and health has stimulated research into the identification of specific microorganisms involved in different processes, and the elucidation of metabolic pathways, particularly those associated with metabolism of dietary components and some host-generated substances. In the first part of the review, we discuss the main gut microorganisms, particularly bacteria, and microbial pathways associated with the metabolism of dietary carbohydrates (to short chain fatty acids and gases), proteins, plant polyphenols, bile acids, and vitamins. The second part of the review focuses on the methodologies, existing and novel, that can be employed to explore gut microbial pathways of metabolism. These include mathematical models, omics techniques, isolated microbes, and enzyme assays

Systematic review of the effects of the intestinal microbiota on selected nutrients and non-nutrients

The systematic review demonstrates that the IM plays a major role in the breakdown and transformation of the dietary substrates examined. However, recent human data are limited with the exception of data from studies examining fibres and polyphenols. Results observed in relation with dietary substrates were not always consistent or coherent across studies and methodological limitations and differences in IM analyses made comparisons difficult. Moreover, non-digestible components likely to reach the colon are often not well defined or characterised in studies making comparisons between studies difficult if not impossible. Going forward, further rigorously controlled randomised human trials with well-defined dietary substrates and utilizing omic-based technologies to characterise and measure the IM and their functional activities will advance the field. Current evidence suggests that more detailed knowledge of the metabolic activities and interactions of the IM hold considerable promise in relation with host health

Comparison of the structural dynamic and mitochondrial electron-transfer properties of the proapoptotic human cytochrome c variants, G41S, Y48H and A51V

Mitochondrial cytochrome c is associated with electron transfer in the respiratory chain and in apoptosis. Four cytochrome c variants have been identified in families that suffer from mild autosomal dominant thrombocytopenia, a platelet disorder associated with increased apoptosis. Three out of the four substitutions, G41S, Y48H and A51V are located on the 40–57 Ω-loop. The G41S and Y48H variants perturb key physicochemical and dynamic properties that result in enhanced functional features associated with apoptotic activity. Herein we characterise the ferric A51V variant. We show by chemical denaturation that this variant causes the native state to be destabilized. Through azide binding kinetics, the population of a pentacoordinate heme form, whereby the Met80 axial ligand is dissociated, is estimated to be of equal magnitude to that found in the Y48H variant. This pentacoordinate form gives rise to peroxidase activity, which despite the similar pentacoordinate population of the A51V variant to that of the Y48H variant, the peroxidase activity of the A51V variant is suppressed. Far-UV circular dichroism spectroscopy and pH jump studies, suggest that a combination of structural and dynamic features in addition to the population of the pentacoordinate form regulate peroxidase activity in these disease variants. Additionally, the steady-state ratio of ferric/ferrous cytochrome c when in turnover with cytochrome c oxidase has been investigated for all 40–57 Ω-loop variants. These studies show that the lower pKa of the alkaline transition for the disease causing variants increases the ferric to ferrous heme ratio, indicating a possible influence on respiration in vivo

Minor-Myosin, a Novel Myosin Isoform Synthesized Preferentially in Drosophila Testis Is Encoded by the Muscle Myosin Heavy-Chain Gene

Item does not contain fulltex

Notfallmedizinische Aspekte bei Laufveranstaltungen

Background!#!The number of short- and long-distance running events in Germany is increasing. Running as a popular sport is practiced by a large number of people of different ages, risk groups, and degrees of professionalism, which results in a wide range of medical emergencies.!##!Objective!#!The present article elucidates incidence, pathophysiology and therapy of relevant emergencies during running events. Aim was the optimization of work processes of emergency personnel.!##!Materials and methods!#!A literature search was conducted in PubMed.!##!Results!#!Exercise-associated muscle cramps, gastrointestinal symptoms, collapse, compartment syndrome, and tendinopathy are common clinical manifestations. Cardiac arrest and sudden cardiac death are rare events. Consciousness and seizures are major complications. Disseminated intravascular coagulation, exercise-associated hyponatremia, heat stroke, rhabdomyolysis, and thromboembolism are associated with high morbidity and mortality. Substances increasing pain resilience as well as performance-enhancing substances are popular among amateur and professional runners and are associated with a high incidence of side effects.!##!Conclusion!#!General symptoms including vomiting, fever, collapse, muscle-pain, nausea and weakness are the leading symptoms during running events. A careful anamnesis is important for targeted clinical therapy. Symptom control is the main task. Fluid management the most challenging task for healthcare providers in the prehospital setting

Medical emergencies during running events

Background The number of short- and long-distance running events in Germany is increasing. Running as a popular sport is practiced by a large number of people of different ages, risk groups, and degrees of professionalism, which results in a wide range of medical emergencies. Objective The present article elucidates incidence, pathophysiology and therapy of relevant emergencies during running events. Aim was the optimization of work processes of emergency personnel. Materials and methods A literature search was conducted in PubMed. Results Exercise-associated muscle cramps, gastrointestinal symptoms, collapse, compartment syndrome, and tendinopathy are common clinical manifestations. Cardiac arrest and sudden cardiac death are rare events. Consciousness and seizures are major complications. Disseminated intravascular coagulation, exercise-associated hyponatremia, heat stroke, rhabdomyolysis, and thromboembolism are associated with high morbidity and mortality. Substances increasing pain resilience as well as performance-enhancing substances are popular among amateur and professional runners and are associated with a high incidence of side effects. Conclusion General symptoms including vomiting, fever, collapse, muscle-pain, nausea and weakness are the leading symptoms during running events. A careful anamnesis is important for targeted clinical therapy. Symptom control is the main task. Fluid management the most challenging task for healthcare providers in the prehospital setting