187 research outputs found
Pathophysiology of Neonatal Transition and Meaningful Measures for the Initial Stabilisation of Extremely Premature Neonates
No full textThis report discusses the physiological aspects of neonatal transition from breathing liquid to air. Further, we discuss reasonable medical interventions to actively assist a gentle transition, and focus on team aspects of preparing both the perinatal team and parents for the challenging situation of preterm labour and delivery. Our aim is to critically evaluate current concepts on the physiology of neonatal transition and the current assessment of the newborn infant, to present means to facilitate non-traumatic pulmonary aeration and ways to foster successful teamwork and professional parental guidance in the delivery room. The authors report on their own work and on that of other research groups, as recently published in peer reviewed medical journals. When born, the newborn needs to rapidly clear his/her lungs from fluid to establish breathing. Active fluid transport and passive resorption help to establish the pulmonary functional residual capacity (FRC). Prenatal administration of corticosteroids helps to form and maintain the FRC of the newborn. Many very low gestational age neonates (ELGAN) will breathe at birth but require medical assistance. This is best done by giving distending positive airway pressure at levels of 5cmH(2)O, or greater. Monitoring of these infants should be by peripheral pulse oximetry. Some ELGANs may require non-invasive ventilation and/or exogenous Surfactant replacement, and even fewer may require intubation and mechanical ventilation. The obstetric and neonatal teams need to coordinate their joined efforts to secure a safe delivery for mother and child. Ways of communication between teams and parents are presented. Many neonatal teams use video recording as a tool to assess and improve their work. We give insights into the use of video as a means to improve teamwork and patient care alike
Dataset related to publication "In silico evaluation of the thermal stress induced by MRI switched gradient fields in patients with metallic hip implant"
No full textThe datasets reported in the figures of the article "In silico evaluation of the thermal stress induced by MRI switched gradient fields in patients with metallic hip implant", published on Phys. Med. Biol. 64 245006, 2019.
This work focuses on the in silico evaluation of the energy deposed by MRI switched gradient fields
in bulk metallic implants and the consequent temperature increase in the surrounding tissues. The results show that the gradient coils can generate local increases of temperature up to some kelvin when acting without radiofrequency excitation. Hence, their contribution in general should not be disregarded when evaluating patients’ safety.The results here reported have been developed in the framework of the 17IND01 MIMAS Project. This project
has received funding from the EMPIR Programme, co-financed by the Participating States and from the
European Union's Horizon 2020 Research and Innovation Programme
Drought stress in maize causes differential acclimation responses of glutathione and sulfur metabolism in leaves and roots
No full textBackground: Drought is the most important environmental stress that limits crop yield in a global warming world. Despite the compelling evidence of an important role of oxidized and reduced sulfur-containing compounds during the response of plants to drought stress (e.g. sulfate for stomata closure or glutathione for scavenging of reactive oxygen species), the assimilatory sulfate reduction pathway is almost not investigated at the molecular or at the whole plant level during drought.
Results: In the present study, we elucidated the role of assimilatory sulfate reduction in roots and leaves of the staple crop maize after application of drought stress. The time-resolved dynamics of the adaption processes to the stress was analyzed in a physiological relevant situation -when prolonged drought caused significant oxidation stress but root growth should be maintained. The allocation of sulfate was significantly shifted to the roots upon drought and allowed for significant increase of thiols derived from sulfate assimilation in roots. This enabled roots to produce biomass, while leaf growth was stopped. Accumulation of harmful reactive oxygen species caused oxidation of the glutathione pool and decreased glutathione levels in leaves. Surprisingly, flux analysis using [S-35]sulfate demonstrated a significant down-regulation of sulfate assimilation and cysteine synthesis in leaves due to the substantial decrease of serine acetyltransferase activity. The insufficient cysteine supply caused depletion of glutathione pool in spite of significant transcriptional induction of glutathione synthesis limiting GSH1. Furthermore, drought impinges on transcription of membrane-localized sulfate transport systems in leaves and roots, which provides a potential molecular mechanism for the reallocation of sulfur upon prolonged water withdrawal.
Conclusions: The study demonstrated a significant and organ-specific impact of drought upon sulfate assimilation. The sulfur metabolism related alterations at the transcriptional, metabolic and enzyme activity level are consistent with a promotion of root growth to search for water at the expense of leaf growth. The results provide evidence for the importance of antagonistic regulation of sulfur metabolism in leaves and roots to enable successful drought stress response at the whole plant level
Alterations of alveolar type II cells and intraalveolar surfactant after bronchoalveolar lavage and perfluorocarbon ventilation. An electron microscopical and stereological study in the rat lung
No full textAbstract Background Repeated bronchoalveolar lavage (BAL) has been used in animals to induce surfactant depletion and to study therapeutical interventions of subsequent respiratory insufficiency. Intratracheal administration of surface active agents such as perfluorocarbons (PFC) can prevent the alveolar collapse in surfactant depleted lungs. However, it is not known how BAL or subsequent PFC administration affect the intracellular and intraalveolar surfactant pool. Methods Male wistar rats were surfactant depleted by BAL and treated for 1 hour by conventional mechanical ventilation (Lavaged-Gas, n = 5) or partial liquid ventilation with PF 5080 (Lavaged-PF5080, n = 5). For control, 10 healthy animals with gas (Healthy-Gas, n = 5) or PF5080 filled lungs (Healthy-PF5080, n = 5) were studied. A design-based stereological approach was used for quantification of lung parenchyma and the intracellular and intraalveolar surfactant pool at the light and electron microscopic level. Results Compared to Healthy-lungs, Lavaged-animals had more type II cells with lamellar bodies in the process of secretion and freshly secreted lamellar body-like surfactant forms in the alveoli. The fraction of alveolar epithelial surface area covered with surfactant and total intraalveolar surfactant content were significantly smaller in Lavaged-animals. Compared with Gas-filled lungs, both PF5080-groups had a significantly higher total lung volume, but no other differences. Conclusion After BAL-induced alveolar surfactant depletion the amount of intracellularly stored surfactant is about half as high as in healthy animals. In lavaged animals short time liquid ventilation with PF5080 did not alter intra- or extracellular surfactant content or subtype composition.</p
Treatment of glioblastoma multiforme cells with temozolomide-BioShuttle ligated by the inverse Diels-Alder ligation chemistry
No full textKlaus Braun1, Manfred Wiessler1, Volker Ehemann2, Ruediger Pipkorn3, Herbert Spring4, Juergen Debus5, Bernd Didinger5, Mario Koch3, Gabriele Muller6, Waldemar Waldeck61German Cancer Research Center, Dept of Imaging and Radiooncology, Heidelberg, Germany; 2University of Heidelberg, Institute of Pathology, Heidelberg, Germany; 3German Cancer Research Center, Central Peptide Synthesis Unit, Heidelberg, Germany; 4German Cancer Research Center, Dept of Structural Analysis of Gene Structure and Function, Heidelberg, Germany; 5University of Heidelberg, Dept of Radiation Oncology, Heidelberg, Germany; 6German Cancer Research Center,Division of Biophysics of Macromolecules, Heidelberg, GermanyAbstract: Recurrent glioblastoma multiforme (GBM), insensitive against most therapeutic interventions, has low response and survival rates. Temozolomide (TMZ) was approved for second-line therapy of recurrent anaplastic astrocytoma. However, TMZ therapy in GBM patients reveals properties such as reduced tolerability and inauspicious hemogram. The solution addressed here concerning GBM therapy consolidates and uses the potential of organic and peptide chemistry with molecular medicine. We enhanced the pharmacologic potency with simultaneous reduction of unwanted adverse reactions of the highly efficient chemotherapeutic TMZ. The TMZ connection to transporter molecules (TMZ-BioShuttle) was investigated, resulting in a much higher pharmacological effect in glioma cell lines and also with reduced dose rate. From this result we can conclude that a suitable chemistry could realize the ligation of pharmacologically active, but sensitive and highly unstable pharmaceutical ingredients without functional deprivation. The TMZ-BioShuttle dramatically enhanced the potential of TMZ for the treatment of brain tumors and is an attractive drug for combination chemotherapy.Keywords: drug delivery, carrier molecules, facilitated transport, glioblastoma multiforme, temozolomid
Risk Sharing and Efficiency Implications of Progressive Pension Arrangements
No full textThe present paper aims to quantify the welfare effects of progressive pension arrangements in Germany. Starting from a purely contribution-related benefit system, we introduce basic allowances for contributions and a flat benefit fraction. Since our overlapping-generations model takes into account variable labor supply, borrowing constraints as well as stochastic income risk, we can compare the labor supply, the liquidity, and the insurance effects of the policy reform. Our simulations indicate that for a realistic parameter combination an increase in pension progressivity would yield an aggregate efficiency gain of more than 2 percent of resources. However, such a reform would not be implemented because it would not find political support of the currently living generations.pension reform, idiosyncratic labor income uncertainty
Coin migration within the euro area
No full textThis paper analyses how many euro coins outflow from Germany and which composition of coins is to be expected in the long run. To this end, a simple mathematical model is formulated and calibrated for €1 coins. The introduction of the euro coins in 2002 presented a unique opportunity to analyse the cross-border migration and the mixing process of coins in different euro-area countries. Based on research by Stoyan and depending on growth assumptions, the annual outflow of German €1 coins is calculated to lie somewhere between 4% and 5%. In the long run, the ratio of German €1 coins in Germany is likely to converge to around 50%. --Euro coins,coin volumes,mixing process
Systems analysis of metabolism and the transcriptome in Arabidopsis thaliana roots reveals differential co-regulation upon iron, sulfur and potassium deficiency
No full textDeprivation of mineral nutrients causes significant retardation of plant growth. This retardation is associated with nutrient specific and general stress-induced transcriptional responses. In this study we adjusted the external supply of iron, potassium and sulfur to cause the same retardation of shoot growth. Nevertheless, limitation by individual nutrients resulted in specific morphological adaptations and distinct shifts within the root metabolite fingerprint. The metabolic shifts affected key metabolites of primary metabolism and the stress-related phytohormones, jasmonic-, salicylic- and abscisic acid. These phytohormone signatures contributed to specific nutrient deficiency-induced transcriptional regulation. Limitation by the micronutrient iron caused the strongest regulation and affected 18 % of the root transcriptome. Only 130 genes were regulated by all nutrients. Specific co-regulation between the iron and sulfur metabolic routes upon iron or sulfur deficiency was observed. Interestingly, iron deficiency caused regulation of a different set of genes of the sulfur assimilation pathway compared to sulfur deficiency itself, which demonstrates the presence of specific signal-transduction systems for the cross-regulation of the pathways. Combined iron and sulfur starvation experiments demonstrated that a requirement for a specific nutrient can overrule this cross-regulation. The comparative metabolomics and transcriptomics approach used dissected general-stress from nutrient-specific regulation in roots of Arabidopsis
Money and monetary policy transmission in the euro area: evidence from FAVAR- and VAR approaches
No full textThis paper investigates the transmission of monetary policy in the euro area based on the factor augmented vector autoregressive approach of Bernanke, Boivin and Eliasz (2005) as well as on a standard VAR model. We focus on the reaction of monetary aggregates to a one-off monetary policy shock. We find that - as theory suggests - money growth is dampened by a restrictive monetary policy stance in the longer term. In the short-run, however, M3 growth may increase due to portfolio shifts caused by the rise in the short-term interest rate. This has consequences for the interpretation of money growth as an input for monetary policy decisions. --Monetary policy transmission,FAVAR,VAR,money stock,euro area.
Equilibrium and Efficiency in the Tug-of-War
No full textWe characterize the unique Markov perfect equilibrium of a tug-of-war without exogenous noise, in which players have the opportunity to engage in a sequence of battles in an attempt to win the war. Each battle is an all-pay auction in which the player expending the greater resources wins. In equilibrium, contest effort concentrates on at most two adjacent states of the game, the "tipping states", which are determined by the contestants' relative strengths, their distances to final victory, and the discount factor. In these states battle outcomes are stochastic due to endogenous randomization. Both relative strength and closeness to victory increase the probability of winning the battle at hand. Patience reduces the role of distance in determining outcomes.Applications range from politics, economics and sports, to biology, where the equilibrium behavior finds empirical support: many species have developed mechanisms such as hierarchies or other organizational structures by which the allocation of prizes are governed by possibly repeated conflict. Our results contribute to an explanation why. Compared to a single-stage conflict, such structures can reduce the overall resources that are dissipated among the group of players.winner-take-all, all-pay auction, tipping, multi-stage contest, dynamic game, preemption, conflict, dominance
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