Interactive Phenomena of a Rotating Arc and a Premixed CH4 Flame

The interactive phenomena between a rotating arc and a premixed methane/air flame have been investigated. The effects of the rotating arc on the flame were observed: both lean and rich flammability limit was extended with the rotating arc on. More interestingly, the opposite interactions, i.e., the effects of the flame on the rotating arc, were also observed: the arc length, angular speed, and electrical characteristics are affected by the flame. An analysis of the optical emission spectra showed that the rotating arc generates chemically active species such as excited N₂ molecules and O and H atoms. An analysis of the gas products indicated that the concentrations of the major gas products such as CO₂, CO, and H₂ were not significantly affected by the rotating arc, although the flammability limit are significantly extended. Unlike these major gas products, minor products like NO_x emissions increased by an order of magnitude in the presence of a rotating arc under certain air/fuel conditions.     

Comparative Study of Methane Activation Process by Different Plasma Sources

In this paper, we compare the characteristics of methane activation by diverse plasma sources. The test conditions of reactant flow rate and composition are fixed for each plasma source to eliminate any possible misleading effects from varying test conditions. Among the diverse characteristics of each plasma source, we focus on the electron energy and degree of thermal activation in evaluating the cost-effectiveness of methane decomposition. The reaction is evaluated based on the selectivity of specific products, including H₂, C₂H₆, and C₂H₂. Among the tested plasma sources, those that provide a somewhat thermal environment have a rather high degree of warmness, resulting in higher methane conversion and lower operational costs. As the non-thermal characteristics of the plasma sources become stronger, the selectivity of C₂H₆ increases. This reflects C₂H₆ formation from the direct collision of CH₄ with high-energy electrons. On the other hand, as the degree of warmness increases, the selectivity of H₂ and C₂H₂ increase. The results give an insight into possible tools for process control or selectivity control by varying the degree of warmness in the plasma source. The process optimization and cost reduction of methane activation should be based on this concept of selectivity control.     

Prediction of African Swine Fever Virus Inhibitors by Molecular Docking-Driven Machine Learning Models

African swine fever virus (ASFV) causes a highly contagious and severe hemorrhagic viral disease with high mortality in domestic pigs of all ages. Although the virus is harmless to humans, the ongoing ASFV epidemic could have severe economic consequences for global food security. Recent studies have found a few antiviral agents that can inhibit ASFV infections. However, currently, there are no vaccines or antiviral drugs. Hence, there is an urgent need to identify new drugs to treat ASFV. Based on the structural information data on the targets of ASFV, we used molecular docking and machine learning models to identify novel antiviral agents. We confirmed that compounds with high affinity present in the region of interest belonged to subsets in the chemical space using principal component analysis and k-means clustering in molecular docking studies of FDA-approved drugs. These methods predicted pentagastrin as a potential antiviral drug against ASFVs. Finally, it was also observed that the compound had an inhibitory effect on AsfvPolX activity. Results from the present study suggest that molecular docking and machine learning models can play an important role in identifying potential antiviral drugs against ASFVs.     

Bestimmung von Zink in Thrombocyten mit INAA und AAS

Zusammenfassung Zur Klärung widersprüchlicher Angaben in der Literatur untersuchten wir die Zinkkonzentration von normalen menschlichen Thrombocyten mit Hilfe der instrumentellen Neutronenaktivierungsanalyse (INAA, n=26) und der Atomabsorptionsspektrophotometrie (AAS, n=5 × 6). Wir fanden folgende Fehlerquellen: Zinkkontamination, fehlerhaftes Thrombocytenfeuchtgewicht, Fehler bei der INAA. In den AAS-Proben (n=5 × 6) untersuchten wir zusätzlich die Konzentrationen von Calcium und Magnesium. Wir stellten fest, daß nach Ausschalten der Fehlerquellen die Normalbereiche (¯x ± 2 s) der Elemente Zink, Calcium und Magnesium viel enger liegen als bisher angenommen. Sie betragen, auf das plasmakorrigierte Thrombocytenfeuchtgewicht bezogen: Zn=26,5–32,3 g/g; Ca= 567–693 g/g; Mg=178–218 g/g.

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Determination of zinc in platelets by INAA and AAS

Summary To clarify discrepancies in the literature we determined the concentration of zinc in normal human platelets using instrumental neutron activation analysis (INAA, n=26) and atomic absorption spectrophotometry (AAS, n=5 × 6). We detected the following sources of error: zinc contamination, erroneous platelet wet weight, errors when using INAA. Additionally, we determined the concentrations of calcium and magnesium in the AAS-samples (n=5 × 6). We observed that after elimination of the sources of error the normal ranges (mean ± 2 SD) for the elements zinc, calcium and magnesium are far closer than hitherto believed. Based on platelet wet weight corrected for plasma, they are: Zn=26.5–32.3 g/g; Ca= 567-693 g/g, Mg =178–218 g/g.

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Herrn Prof. Dr. W. Fresenius zum 70. Geburtstag gewidmet     

Selective human serum albumin sensor from the screening of a fluorescent rosamine library

A fluorescent dye library approach for the development of a bioanalyte sensor was sought. The screening of a rosamine dye library against diverse macromolecules led to the discovery of a highly sensitive human serum albumin binder, G13, with approximately 36-fold fluorescence intensity change. G13 showed a highly selective response to HSA over other macromolecules including albumins from other species. The potential use of G13 for the detection of HSA in biofluids is described.     

Chemical constituents from the leaves of Manglietia phuthoensis and their effects on osteoblastic MC3T3-E1 cells

Two new phenyl glycosides, mangliesides A and B (1, 2), a new ionol glycoside, manglieside C (3), two new lignan glycosides, mangliesides D and E (4, 5), were isolated from the leaves of Manglietia phuthoensis, along with two known lignans, 3-methoxymagnolol (6) and obovatol (7). Their structures were established by means of 1D and 2D NMR, electrospray ionization (ESI)-MS and HR-ESI-MS experiments. Among them, compounds 2 and 5 significantly (p<0.05) increased the growth and differentiation of osteoblastic MC3T3-E1 cells in vitro.     

Combinatorial dapoxyl dye library and its application to site selective probe for human serum albumin

The combinatorial fluorescent dapoxyl dye library was prepared by both solution- and solid-phase synthesis, generating 80 unique dapoxyl derivatives. A fluorescence-based screening toward human serum albumin (HSA) found one highly sensitive HSA binder ( A41-S) with over 55-fold intensity change. Displacement assay showed the selective binding of A41-S to the site I of HSA, addressing its potential to be a highly selective and sensitive HSA probe.