Molecular cloud formation with self-consistent thermal and chemical treatment of the gas

Understanding physical and chemical processes that guide the formation and evolution of giant molecular clouds (GMCs) has important implications for the formation of stars. GMCs dominantly consist of molecular hydrogen, but there are more than 200 chemical species of various combinations of carbon, nitrogen and oxygen atoms. Together, these species control the cooling ability with the thermal and dynamical evolution of the gas cloud. In order to overcome the restrictions encountered by most previous models of molecular cloud formation due to the complexity of chemical reaction networks and its inclusion in hydrodynamical codes, we have implemented detailed treatment of atomic/molecular cooling and hydrogen chemistry into state-of-art high resolution hydrodynamical simulations. The main focus of our study is on the influence that choosing between different cooling functions and turbulent driving has on the formation and evolution of molecular gas. In that manner, we study the influence of the nature of the turbulence on the formation of molecular hydrogen by examining both solenoidal (divergence-free) and compressive (curl-free) turbulent driving. The obtained results we use to test a simple prescription suggested by Gnedin et al. (2009) for modelling the influence of unresolved density fluctuations on the H2 formation rate in largescale simulations of the ISM. We also investigate the properties of the dense clumps formed within our model of the molecular cloud formation in converging flows and directly compare the results obtained using the simple, parametrized cooling function introduced by Koyama & Inutsuka (2002) and used by a number of converging flows studies with the results of the detailed calculation of the non-equilibrium chemistry and thermal balance of the gas. Finally, we study C I and CO emission from molecular clouds in comparison to their column densities and the total column density, as we look for the way to trace the structure of the cloud

Marine Toxins Targeting Kv1 Channels: Pharmacological Tools and Therapeutic Scaffolds

Toxins from marine animals provide molecular tools for the study of many ion channels, including mammalian voltage-gated potassium channels of the Kv1 family. Selectivity profiling and molecular investigation of these toxins have contributed to the development of novel drug leads with therapeutic potential for the treatment of ion channel-related diseases or channelopathies. Here, we review specific peptide and small-molecule marine toxins modulating Kv1 channels and thus cover recent findings of bioactives found in the venoms of marine Gastropod (cone snails), Cnidarian (sea anemones), and small compounds from cyanobacteria. Furthermore, we discuss pivotal advancements at exploiting the interaction of κM-conotoxin RIIIJ and heteromeric Kv1.1/1.2 channels as prevalent neuronal Kv complex. RIIIJ’s exquisite Kv1 subtype selectivity underpins a novel and facile functional classification of large-diameter dorsal root ganglion neurons. The vast potential of marine toxins warrants further collaborative efforts and high-throughput approaches aimed at the discovery and profiling of Kv1-targeted bioactives, which will greatly accelerate the development of a thorough molecular toolbox and much-needed therapeutics

Risk factors associated with poor clinical outcome in pyogenic spinal infections : 5-years’ intensive care experience

Introduction: Management of pyogenic spinal infections (PSI) after the development of neurological deficit has not been specifically addressed in the literature. We aimed to describe real-life clinical outcomes of PSI in patients admitted to an intensive care unit with neurological deficit and identify factors associated with good prognosis. Methodology: Consecutive patients admitted to ICU with a possible diagnosis of spinal infection over five years’ period were included. Descriptive statistics were performed to examine the demographics and clinical parameters. Results: The majority (71%) of patients were male. The mean age was 57.4 years (27-79), and 71% were > 50 years old. At least one underlying risk factor was identified in 68% of the patients; the most common comorbidity was diabetes mellitus (DM). All patients have presented with fever accompanied by a neurological deficit (86%) and back pain (79%). A complete recovery was achieved in 25% of patients. However, the majority of patients had adverse outcomes with 21.4% mortality, and 43% remaining neurological sequelae. Increased age with a cut-off of 65 years and pre-existing DM were identified as being associated with poor outcome. Conclusion: Mortality among patients admitted to ICU with PSI was significantly higher than reported in the literature. The residual neurological deficit was common, one-third of patients had remaining neurological sequelae, and only one-fourth had complete recovery. Increased age and background DM were the most important determinants of poor clinical outcome. The impact of DM appears to be much more important than currently recognised in this population.Publisher PDFPeer reviewe

Modeling H2 formation in the turbulent ISM: Solenoidal versus compressive turbulent forcing

We present results from high-resolution three-dimensional simulations of the turbulent interstellar medium that study the influence of the nature of the turbulence on the formation of molecular hydrogen. We have examined both solenoidal (divergence-free) and compressive (curl-free) turbulent driving, and show that compressive driving leads to faster H2 formation, owing to the higher peak densities produced in the gas. The difference in the H2 formation rate can be as much as an order of magnitude at early times, but declines at later times as the highest density regions become fully molecular and stop contributing to the total H2 formation rate. We have also used our results to test a simple prescription suggested by Gnedin et al. (2009) for modeling the influence of unresolved density fluctuations on the H2 formation rate in large-scale simulations of the ISM. We find that this approach works well when the H2 fraction is small, but breaks down once the highest density gas becomes fully molecular.Comment: 13 pages, 8 figures, accepted for publication in MNRA

Tailor-made biocatalysts based on scarcely studied acidic horseradish peroxidase for biodegradation of reactive dyes

Peroxidases (EC 1.11.1.7) have enormous biotechnological applications. Usage of more abundant, basic isoforms of peroxidases in diagnostic kits and/or in immunochemistry has led to under exploitation and disregard of horseradish peroxidase (HRP) acidic isoforms. Therefore, acidic horseradish peroxidase (HRP-A) isoenzymewas used for the preparation of a biocatalyst with improved ability in dye decolorization. Ten biocatalysts were prepared by covalent binding of enzyme to chitosan and alginate, adsorption followed by cross-linking on inorganic support (aluminum oxide), and encapsulation in spherical calcium alginate beads via polyethylene glycol. Model dyes of 50 to 175 mg l(-1) were removed by the biocatalysts. Among the tested biocatalysts, the three with the highest specific activity and biodegradation rate were further studied (Chitosan-HRP, Al-GelHRP and Al-HRP-Gel). The impact of hydrogen peroxide concentration on dye decolorization was examined on the Chitosan-HRP biocatalyst, since the HRP is susceptible to inhibition/inactivation by high H2O2. On the other hand, H2O2 is needed as a co-substrate for the HRP, and the H2O2/dye ratio can greatly influence decolorization efficiency. Concentrations of H2O2 ranging from 0.22 to 4.4 mM showed no difference in terms of impact on the biocatalyst decolorization efficiency. The high decolorization efficiency of the biocatalysts was validated by the removal of 25 and 100 mg l(-1) anthraquinone (Remazol Brilliant Blue R (RBBR)), triphenylmethane (Coomassie Brilliant Blue CBB)), acridine (Acridine Orange (AO)), and formazan metal complex dye (Reactive Blue 52 (RB52)). After the seven consecutive decolorization cycles, the decolorization was still 53, 78, and 67% of the initial dye for the Al-HRP-Gel, Al-Gel-HRP, and Chitosan-HRP immobilizate, respectively. The results obtained showed potential of otherwise neglected acidic HRP isoforms as a cost-effective biocatalyst with significant potential in wastewater dyestuff treatment

Korrosionsschutz von luftfahrtrelevanten Werkstoffen durch Ionenstrahlverfahren

Aluminium coating with additive magnesium and lithium was examined as an alternative to anticorrosive coating of titanium alloys and stainless steel by means of cadmium/chromate coating. Additional coatings of CrN, AlN, 4C30, titanium compounds as well as simple coatings with hard materials were examined for their suitability for wearing protection. Aluminium combined with CrN or ALN makes for coatings equal to cadmium/chromate in terms of corrosion prevention. It is impossible to define a 'best' coating because differing manufacturing processes make for different structures and layer thicknesses, even for a given material composition. However, the greater the carbon content of a coating, the greater the corrosiveness of aluminium. On the other hand, a high carbon content leads to improved mechanical properties and 4C30 coatings on soft materials even resist strong tribological stress. (orig./MM)Als Ersatz fuer Kadmium-/Chromatueberzuege auf Titanlegierungen und nichtrostenden Staehlen wurden Aluminiumschichten mit Beimengungen von Magnesium und Lithium als Korrosionsschutzschichten sowie mit zusaetzlichen Ueberzuegen von CrN, AlN, 4C30 und Ti-Verbindungen als Schutz vor Verschleiss sowie Hartstoffverbindungen allein untersucht. Einen zu Kadmium/Chromat -gleichwertigen Korrosionsschutz bieten die Al-Kombinationen mit CrN bzw. ALN als Deckschicht. Wegen der herstellungsbedingten Struktur- und Schichtdickenunterschiede auch bei Schichten gleicher Zusammensetzung kann keine 'beste' Schicht definiert werden. Die Hartstoffschichten sind saemtlich resistent gegen kuenstliche Klimate. Sie fuehren aber zu verstaerkter Korrosion von Aluminium, je hoeher ihr Kohlenstoffanteil ist. Gleichzeitig verbessert sich aber die Reibcharakteristik und Ueberzuege wie 4C30 halten sogar auf weichen Grundwerkstoffen hohen tribologischen Belastungen Stand. (orig./MM)SIGLEAvailable from TIB Hannover: F93B1370 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany)DEGerman

Prenatal monitoring of pregnancies complicated by diabetes mellitus

Preconception and prenatal monitoring evaluate the condition of the mother's underlying disease and possible complications during pregnancy. Before conception, patients with diabetes should be informed that suboptimal glycoregulation is associated with reduced fertility and pregnancy losses. The task of the perinatologist in pregnancies affected by diabetes mellitus is to prevent complications of the underlying disease, such as hypoglycemic crises. Another important component of prenatal care in diabetic pregnancies is the recognition and prevention of pregnancy complications such as preeclampsia, polyhydramnios, congenital malformations, fetal macrosomia, and infections

In vitro antiglioma action of indomethacin is mediated via AMP-activated protein kinase/mTOR complex 1 signalling pathway

We investigated the role of the intracellular energy-sensing AMP-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) pathway in the in vitro antiglioma effect of the cyclooxygenase (COX) inhibitor indomethacin. Indomethacin was more potent than COX inhibitors diclofenac, naproxen, and ketoprofen in reducing the viability of U251 human glioma cells. Antiglioma effect of the drug was associated with p21 increase and G2M cell cycle arrest, as well as with oxidative stress, mitochondrial depolarization, caspase activation, and the induction of apoptosis. Indomethacin increased the phosphorylation of AMPK and its targets Raptor and acetyl-CoA carboxylase (ACC), and reduced the phosphorylation of mTOR and mTOR complex 1 (mTORC1) substrates p70S6 kinase and PRAS40 (Ser183). AMPK knockdown by RNA interference, as well as the treatment with the mTORC1 activator leucine, prevented indomethacin-mediated mTORC1 inhibition and cytotoxic action, while AMPK activators metformin and AICAR mimicked the effects of the drug. AMPK activation by indomethacin correlated with intracellular ATP depletion and increase in AMP/ATP ratio, and was apparently independent of COX inhibition or the increase in intracellular calcium. Finally, the toxicity of indomethacin towards primary human glioma cells was associated with the activation of AMPK/Raptor/ACC and subsequent suppression of mTORC1/S6K. By demonstrating the involvement of AMPK/mTORC1 pathway in the antiglioma action of indomethacin, our results support its further exploration in glioma therapy.The International Journal of Biochemistry & Cell Biology (2017), 83: 84-9