1,158 research outputs found
Diorganotin compounds containing α-aminoacidato schiff base ligands derived from functionalized 2-Hydroxy-5-(aryldiazenyl)benzaldehyde
Three novel bicycloazastannoxides, namely, [nBu2Sn(L1)] (1), [nBu2Sn(L2)] (2) and [Bz2Sn(L3)] (3) were synthesized in one pot procedures by reacting diorganotin(IV) precursors with a mixture composed of an α-amino acid with either (E)-2-hydroxy-5-((4-nitrophenyl)diazenyl)benzaldehyde or (E)-2-hydroxy-5-(phenyldiazenyl)benzaldehyde. Single-crystal X-ray diffraction analysis reveal that compound 1 is monomeric, compound 2 consists of both a monomer and a dimer, while compound 3 is a coordination polymer for which two modifications 3A and 3B were identified. The 119Sn NMR chemical shifts measured in CDCl3 solutions indicate five-coordinate tin atoms for 1–3. Further, compounds 1 and 2 were found to be highly selective for sensing hydrogen sulfide in UV/Vis channel in CH3CN/H2O (9:1) media. The development of orange red color is likely the results of a Brønsted-type acid-base reaction of H2S with compounds 1 and 2, respectively, giving di-n-butyltin sulfide and the corresponding pro-ligands H2L1 and H2L2, respectively. Theoretical calculations accompany the experimental work
Characterization and Optimization of a Conical Corona Reactor for Seed Treatment of Rapeseed
Plasma agriculture is a growing field that combines interdisciplinary areas with the aim of researching alternative solutions for increasing food production. In this field, plasma sources are used for the treatment of different agricultural goods in pre-and post-harvest. With the big variety of possible treatment targets, studied reactors must be carefully investigated and characterized for specific goals. Therefore, in the present study, a cone-shaped corona reactor working with argon was adapted for the treatment of small seeds, and its basic properties were investigated. The treatment of rapeseed using different voltage duty cycles led to an increase in surface wettability, possibly contributing to the accelerated germination (27% for 90% duty cycle). The discharge produced by the conical reactor was able to provide an environment abundant with reactive oxygen species that makes the process suitable for seeds treatment. However, operating in direct treatment configuration, large numbers of seeds placed in the reactor start impairing the discharge homogeneity
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Elevated H2AX Phosphorylation Observed with kINPen Plasma Treatment Is Not Caused by ROS-Mediated DNA Damage but Is the Consequence of Apoptosis
Phosphorylated histone 2AX (γH2AX) is a long-standing marker for DNA double-strand breaks (DSBs) from ionizing radiation in the field of radiobiology. This led to the perception of γH2AX being a general marker of direct DNA damage with the treatment of other agents such as low-dose exogenous ROS that unlikely act on cellular DNA directly. Cold physical plasma confers biomedical effects majorly via release of reactive oxygen and nitrogen species (ROS). In vitro, increase of γH2AX has often been observed with plasma treatment, leading to the conclusion that DNA damage is a direct consequence of plasma exposure. However, increase in γH2AX also occurs during apoptosis, which is often observed with plasma treatment as well. Moreover, it must be questioned if plasma-derived ROS can reach into the nucleus and still be reactive enough to damage DNA directly. We investigated γH2AX induction in a lymphocyte cell line upon ROS exposure (plasma, hydrogen peroxide, or hypochlorous acid) or UV-B light. Cytotoxicity and γH2AX induction was abrogated by the use of antioxidants with all types of ROS treatment but not UV radiation. H2AX phosphorylation levels were overall independent of analyzing either all nucleated cells or segmenting γH2AX phosphorylation for each cell cycle phase. SB202190 (p38-MAPK inhibitor) and Z-VAD-FMK (pan-caspase inhibitor) significantly inhibited γH2AX induction upon ROS but not UV treatment. Finally, and despite γH2AX induction, UV but not plasma treatment led to significantly increased micronucleus formation, which is a functional read-out of genotoxic DNA DSBs. We conclude that plasma-mediated and low-ROS γH2AX induction depends on caspase activation and hence is not the cause but consequence of apoptosis induction. Moreover, we could not identify lasting mutagenic effects with plasma treatment despite phosphorylation of H2AX
Early onset of treatment effects with oral risperidone
BACKGROUND: The dogma of a delayed onset of antipsychotic treatment effects has been maintained over the past decades. However, recent studies have challenged this concept. We therefore performed an analysis of the onset of antipsychotic treatment effects in a sample of acutely decompensated patients with schizophrenia. METHODS: In this observational study, 48 inpatients with acutely decompensated schizophrenia were offered antipsychotic treatment with oral risperidone. PANSS-ratings were obtained on day 0, day 1, day 3, day 7 and day 14. RESULTS: Significant effects of treatment were already present on day 1 and continued throughout the study. The PANSS positive subscore and the PANSS total score improved significantly more than the PANSS negative subscore. CONCLUSION: Our results are consistent with the growing number of studies suggesting an early onset of antipsychotic treatment effects. However, non-pharmacological effects of treatment also need to be taken into consideration
Intersecting 6-branes from new 7-manifolds with G_2 holonomy
We discuss a new family of metrics of 7-manifolds with G_2 holonomy, which
are R^3 bundles over a quaternionic space. The metrics depend on five
parameters and have two Abelian isometries. Certain singularities of the G_2
manifolds are related to fixed points of these isometries; there are two
combinations of Killing vectors that possess co-dimension four fixed points
which yield upon compactification only intersecting D6-branes if one also
identifies two parameters. Two of the remaining parameters are quantized and we
argue that they are related to the number of D6-branes, which appear in three
stacks. We perform explicitly the reduction to the type IIA model.Comment: 25 pages, 1 figure, Latex, small changes and add refs, version
appeared in JHE
Design of a web-based LBS framework addressing usability, cost, and implementation constraints
This research investigates barriers that prevent Location Based Services (LBS) from reaching its full potential. The different constraints, including poor usability, lack of positioning support, costs, and integration difficulties are highlighted. A framework was designed incorporating components based on existing and new technologies that could help address the constraints of LBS and increase end-user acceptance. This research proposes that usability constraints can be addressed by adapting a system to user characteristics which are inferred on the basis of captured user context and interaction data. A prototype LBS system was developed to prove the feasibility and benefit of the framework design, demonstrating that constraints of positioning, cost, and integration can be overcome. Volunteers were asked to use the system, and to answer questions in relation to their proficiency and experience. User-feedback showed that the proposed combination of functionality was well-received, and the prototype was appealing to many users. Ground-truths from the survey were related back to data captured with a user monitoring component in order to investigate whether users can be classified according to their context and how they interact. The results have shown that statistically significant relationships exist, and that by using the C4.5 decision-tree, computer proficiency can be estimated within one class-width in 76.7% of the cases. These results suggest that it may be possible to build a user-model to estimate computer proficiency on the basis of user-interaction data. The user model could then used to improve usability through adaptive user-specific customisations
Influence of alkaline modification on adsorption properties of aluminum oxide
In this work the adsorption capacity of samples A-2-9С, A-2-Na-9С, A-2-K-9С was studied. It was found that alkaline modification leads to an increase in the efficiency of aluminum oxide dehydrators
Precise verification of phase and amplitude calibration by means of a debunching experiment in SIS18
Several new rf cavity systems have to be realized for the
FAIR synchrotrons and for the upgrade of the existing GSI
synchrotron SIS18 [1]. For this purpose, a completely new
low-level rf (LLRF) system architecture [2] has been developed, which is now used in SIS18 operation. Closedloop control systems stabilize the amplitude and the phase
of the rf gap voltages. Due to component imperfections
the transmission and the detection of the actual values lead
to systematic errors without countermeasures. These errors prohibit the operation of the rf systems over the whole
amplitude and frequency range within the required accuracy. To compensate the inevitable errors, the target values
provided by the central control system are modified by socalled calibration electronics (CEL, [3]) modules. The calibration curves can be measured without the beam, but the
desired beam behaviour has to be verified by experiments.
For this purpose, a debunching scenario was selected as a
SIS18 beam experiment that proved to be very sensitive to
inaccuracies. In this contribution the results of this experiment are presented, showing for the first time at GSI by
beam observation that the accuracy requirements are met
based on predefined calibration curves
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