35 research outputs found

    Measurement of local crystal lattice strain variations in dealloyed nanoporous gold

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    Reversible macroscopic length changes in nanoporous structures can be achieved by applying electric potentials or by exposing them to different gases or liquids. Thus, these materials are interesting candidates for applications as sensors or actuators. Macroscopic length changes originate from microscopic changes of crystal lattice parameters. In this report, we show spatially resolved measurements of crystal lattice strain in dealloyed nanoporous gold. The results confirm theory by indicating a compression of the lattice along the axis of cylindrically shaped ligaments and an expansion in radial direction. Furthermore, we show that curved npAu surfaces show inward relaxation of the surface layer. (Figure presented) IMPACT STATEMENT We show spatially resolved measurements of strain in nanoporous gold confirming theory: Crystal lattice is compressed along the axis of cylindrical ligaments and expanded in radial direction, surfaces relax inward

    Effect of aliskiren on post-discharge outcomes among diabetic and non-diabetic patients hospitalized for heart failure: insights from the ASTRONAUT trial

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    Aims The objective of the Aliskiren Trial on Acute Heart Failure Outcomes (ASTRONAUT) was to determine whether aliskiren, a direct renin inhibitor, would improve post-discharge outcomes in patients with hospitalization for heart failure (HHF) with reduced ejection fraction. Pre-specified subgroup analyses suggested potential heterogeneity in post-discharge outcomes with aliskiren in patients with and without baseline diabetes mellitus (DM). Methods and results ASTRONAUT included 953 patients without DM (aliskiren 489; placebo 464) and 662 patients with DM (aliskiren 319; placebo 343) (as reported by study investigators). Study endpoints included the first occurrence of cardiovascular death or HHF within 6 and 12 months, all-cause death within 6 and 12 months, and change from baseline in N-terminal pro-B-type natriuretic peptide (NT-proBNP) at 1, 6, and 12 months. Data regarding risk of hyperkalaemia, renal impairment, and hypotension, and changes in additional serum biomarkers were collected. The effect of aliskiren on cardiovascular death or HHF within 6 months (primary endpoint) did not significantly differ by baseline DM status (P = 0.08 for interaction), but reached statistical significance at 12 months (non-DM: HR: 0.80, 95% CI: 0.64-0.99; DM: HR: 1.16, 95% CI: 0.91-1.47; P = 0.03 for interaction). Risk of 12-month all-cause death with aliskiren significantly differed by the presence of baseline DM (non-DM: HR: 0.69, 95% CI: 0.50-0.94; DM: HR: 1.64, 95% CI: 1.15-2.33; P < 0.01 for interaction). Among non-diabetics, aliskiren significantly reduced NT-proBNP through 6 months and plasma troponin I and aldosterone through 12 months, as compared to placebo. Among diabetic patients, aliskiren reduced plasma troponin I and aldosterone relative to placebo through 1 month only. There was a trend towards differing risk of post-baseline potassium ≥6 mmol/L with aliskiren by underlying DM status (non-DM: HR: 1.17, 95% CI: 0.71-1.93; DM: HR: 2.39, 95% CI: 1.30-4.42; P = 0.07 for interaction). Conclusion This pre-specified subgroup analysis from the ASTRONAUT trial generates the hypothesis that the addition of aliskiren to standard HHF therapy in non-diabetic patients is generally well-tolerated and improves post-discharge outcomes and biomarker profiles. In contrast, diabetic patients receiving aliskiren appear to have worse post-discharge outcomes. Future prospective investigations are needed to confirm potential benefits of renin inhibition in a large cohort of HHF patients without D

    DIY Methods 2022 Conference Proceedings

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    As the past years have proven, the methods for conducting and distributing research that we’ve inherited from our disciplinary traditions can be remarkably brittle in the face of rapidly changing social and mobility norms. The ways we work and the ways we meet are questions newly opened for practical and theoretical inquiry; we both need to solve real problems in our daily lives and account for the constitutive effects of these solutions on the character of the knowledge we produce. Methods are not neutral tools, and nor are they fixed ones. As such, the work of inventing, repairing, and hacking methods is a necessary, if often underexplored, part of the wider research process. This conference aims to better interrogate and celebrate such experiments with method. Borrowing from the spirit and circuits of exchange in earlier DIY cultures, it takes the form of a zine ring distributed via postal mail. Participants will craft zines describing methodological experiments and/or how-to guides, which the conference organisers will subsequently mail out to all participants. Feedback on conference proceedings will also proceed through the mail, as well as via an optional Twitter hashtag. The conference itself is thus an experiment with different temporalities and medialities of research exchange. As a practical benefit, this format guarantees that the experience will be free of Zoom fatigue, timezone difficulties, travel expenses, and visa headaches. More generatively, it may also afford slower thinking, richer aesthetic possibilities, more diverse forms of circulation, and perhaps even some amount of delight. The conference format itself is part of the DIY experiment

    The impact of culture on the strategy of MNCs - a case study of Nestlé

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    In einer globalisierten Welt müssen multinationale Unternehmen ihre Aktivitäten unter Berücksichtigung eines kulturell diversifizierten globalen Umfelds internationalisieren um wettbewerbsfähig zu sein und um Geschäftsziele auf internationalen Märkten zu erreichen. Heutzutage definiert internationales Business neue Ansätze zur weltweiten Steuerung der Aktivitäten des Unternehmens. Aus diesem Grund ist es wichtig zu verstehen wie ein internationales Unternehmen effektiv auf die Herausforderungen reagieren kann, die durch das interkulturelle Umfeld verursacht werden. Des Weiteren sollte versucht werden, die Fähigkeiten seiner ausländischen Tochtergesellschaften voll auszunutzen. Unter Berücksichtigung der Belastungen durch äußere und innere Kräfte werden in dieser Arbeit die wichtigsten Determinanten kultureller Wirksamkeit veranschaulicht. Insbesondere werden Evolutionstheorien multinationaler Unternehmen vorgestellt, die sich auf kulturelle Fragen konzentrieren - Hofstedes Modelle kultureller Dimensionen, Integration/Responsiveness-Modell, Bartlett und Goshals Organisationsmodelle, Perlmutters EPRG-Konzept und Adlers Modelle des interkulturellen Managements. Ein weiteres Ziel dieser Masterarbeit ist es, zu analysieren, welche Rolle der kulturelle Faktor bei der Strategieentwicklung von MNC in einem Tochterunternehmen spielt. Zu diesem Zweck wird sich die Forschung auf die FMCG-Industrie und insbesondere auf den Marktführer - Nestlé Company - konzentrieren.In condition of globalized world in order to be competitive and to reach business objectives in international markets, multinational companies need to internationalize their activities considering culturally diversified global environment. Today’s international business defines new approaches in managing company’s activities worldwide. Due to this fact, it becomes important to understand how an international company can effectively respond to the challenges caused by cross-cultural external environment as well as fully utilize capabilities of its foreign subsidiaries. Thus, taking into account pressures of external and internal forces this thesis considers the main determinants of cultural effectiveness. In particular, will be presented evolutionary theories of multinational companies focused on cultural issues - Hofstede’s models of cultural dimensions, Integration-responsiveness framework, Bartlett and Goshal’s organizational models, Perlmutter’s EPRG concept and Adler’s models of cross-cultural management. Another aim of this thesis was to analyze what role plays cultural factor in strategy development of MNC in subsidiary. For this purpose research was focused on the FMCG industry and specifically on the market leader – Nestlé Company

    Delayed Influence of Spinal Cord Injury on the Amino Acids of NO• Metabolism in Rat Cerebral Cortex Is Attenuated by Thiamine

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    Severe spinal cord injuries (SCIs) result in chronic neuroinflammation in the brain, associated with the development of cognitive and behavioral impairments. Nitric oxide (NO•) is a gaseous messenger involved in neuronal signaling and inflammation, contributing to nitrosative stress under dysregulated production of reactive nitrogen species. In this work, biochemical changes induced in the cerebral cortex of rats 8 weeks after SCI are assessed by quantification of the levels of amino acids participating in the NO• and glutathione metabolism. The contribution of the injury-induced neurodegeneration is revealed by comparison of the SCI- and laminectomy (LE)-subjected animals. Effects of the operative interventions are assessed by comparison of the operated (LE/SCI) and non-operated animals. Lower ratios of citrulline (Cit) to arginine (Arg) or Cit to ornithine and a more profound decrease in the ratio of lysine to glycine distinguish SCI animals from those after LE. The data suggest decreased NO• production from both Arg and homoarginine in the cortex 8 weeks after SCI. Both LE and SCI groups show a strong decrease in the level of cortex glutathione. The neurotropic, anti-inflammatory, and antioxidant actions of thiamine (vitamin B1) prompted us to study the thiamine effects on the SCI-induced changes in the NO• and glutathione metabolism. A thiamine injection (400 mg/kg intraperitoneally) within 24 h after SCI abrogates the changes in the cerebral cortex amino acids related to NO•. Thiamine-induced normalization of the brain glutathione levels after LE and SCI may involve increased supply of glutamate for glutathione biosynthesis. Thus, thiamine protects from sequelae of SCI on NO•-related amino acids and glutathione in cerebral cortex

    Cellular thiamine status is coupled to function of mitochondrial 2-oxoglutarate dehydrogenase

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    Decreased thiamine and reduced activity of thiamine diphosphate (ThDP)-dependent 2-oxoglutarate dehydrogenase (OGDH) cause neurodegeneration. We hypothesized on concerted cell-specific regulation of the thiamine metabolism and ThDP-dependent reactions. We identified a smaller thiamine pool, a lower expression of the mitochondrial ThDP transporter, and a higher expression of OGDH in rat astrocytes versus neuroblastoma N2A. According to the data, the astrocytic OGDH may be up-regulated by an increase in intracellular ThDP, while the neuroblastomal OGDH functions at full ThDP saturation. Indeed, in rat astrocytes and brain cortex, OGDH inhibition by succinyl phosphonate (SP) enlarged the pool of thiamine compounds. Increased ThDP level in response to the OGDH inhibition presumably up-regulated the enzyme to compensate for a decrease in reducing power which occurred in SP-treated astrocytes. Under the same SP treatment of N2A cells, their thiamine pool and reducing power were unchanged, although SP action was evident from accumulation of glutamate. The presented data indicate that functional interplay between OGDH, other proteins of the tricarbocylic acid cycle and proteins of thiamine metabolism is an important determinant of physiology-specific networks and their homeostatic mechanisms

    Hypoxic Adaptation of Mitochondrial Metabolism in Rat Cerebellum Decreases in Pregnancy

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    Function of brain amino acids as neurotransmitters or their precursors implies changes in the amino acid levels and/or metabolism in response to physiological and environmental challenges. Modelling such challenges by pregnancy and/or hypoxia, we characterize the amino acid pool in the rat cerebellum, quantifying the levels and correlations of 15 amino acids and activity of 2-oxoglutarate dehydrogenase complex (OGDHC). The parameters are systemic indicators of metabolism because OGDHC limits the flux through mitochondrial TCA cycle, where amino acids are degraded and their precursors synthesized. Compared to non-pregnant state, pregnancy increases the cerebellar content of glutamate and tryptophan, decreasing interdependence between the quantified components of amino acid metabolism. In response to hypoxia, the dependence of cerebellar amino acid pool on OGDHC and the average levels of arginine, glutamate, lysine, methionine, serine, phenylalanine, and tryptophan increase in non-pregnant rats only. This is accompanied by a higher hypoxic resistance of the non-pregnant vs. pregnant rats, pointing to adaptive significance of the hypoxia-induced changes in the cerebellar amino acid metabolism. These adaptive mechanisms are not effective in the pregnancy-changed metabolic network. Thus, the cerebellar amino acid levels and OGDHC activity provide sensitive markers of the physiology-dependent organization of metabolic network and its stress adaptations

    Daytime Dependence of the Activity of the Rat Brain Pyruvate Dehydrogenase Corresponds to the Mitochondrial Sirtuin 3 Level and Acetylation of Brain Proteins, All Regulated by Thiamine Administration Decreasing Phosphorylation of PDHA Ser293

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    Coupling glycolysis and mitochondrial tricarboxylic acid cycle, pyruvate dehydrogenase (PDH) complex (PDHC) is highly responsive to cellular demands through multiple mechanisms, including PDH phosphorylation. PDHC also produces acetyl-CoA for protein acetylation involved in circadian regulation of metabolism. Thiamine (vitamin B1) diphosphate (ThDP) is known to activate PDH as both coenzyme and inhibitor of the PDH inactivating kinases. Molecular mechanisms integrating the function of thiamine-dependent PDHC into general redox metabolism, underlie physiological fitness of a cell or an organism. Here, we characterize the daytime- and thiamine-dependent changes in the rat brain PDHC function, expression and phosphorylation, assessing their impact on protein acetylation and metabolic regulation. Morning administration of thiamine significantly downregulates both the PDH phosphorylation at Ser293 and SIRT3 protein level, the effects not observed upon the evening administration. This action of thiamine nullifies the daytime-dependent changes in the brain PDHC activity and mitochondrial acetylation, inducing diurnal difference in the cytosolic acetylation and acetylation of total brain proteins. Screening the daytime dependence of central metabolic enzymes and proteins of thiol/disulfide metabolism reveals that thiamine also cancels daily changes in the malate dehydrogenase activity, opposite to those of the PDHC activity. Correlation analysis indicates that thiamine abrogates the strong positive correlation between the total acetylation of the brain proteins and PDHC function. Simultaneously, thiamine heightens interplay between the expression of PDHC components and total acetylation or SIRT2 protein level. These thiamine effects on the brain acetylation system change metabolic impact of acetylation. The changes are exemplified by the thiamine enhancement of the SIRT2 correlations with metabolic enzymes and proteins of thiol-disulfide metabolism. Thus, we show the daytime- and thiamine-dependent changes in the function and phosphorylation of brain PDHC, contributing to regulation of the brain acetylation system and redox metabolism. The daytime-dependent action of thiamine on PDHC and SIRT3 may be of therapeutic significance in correcting perturbed diurnal regulation

    Silver-rich clusters in nanoporous gold

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    High-resolution elemental mapping in a transmission electron microscope shows that the residual silver in dealloying-made nanoporous gold (NPG) is aggregated in nanoscale clusters. Kinetic Monte Carlo simulation confirms that these regions are buried relics of the master alloy that have never been exposed to corrosion. The surface of as-dealloyed NPG is covered by at least one atomic monolayer of nearly pure gold. The preferential location of silver in the bulk is relevant when interfaces control the material's function, as in catalysis and sensing. Annealing in air homogenizes the alloy by surface diffusion
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