414 research outputs found
Nitsche's prescription of Dirichlet conditions in the finite element approximation of Maxwell's problem
In this paper we consider the finite element approximation of Maxwell's
problem and analyse the prescription of essential boundary conditions in a weak
sense using Nitsche's method. To avoid indefiniteness of the problem, the
original equations are augmented with the gradient of a scalar field that
allows one to impose the zero divergence of the magnetic induction, even if the
exact solution for this scalar field is zero. Two finite element approximations
are considered, namely, one in which the approximation spaces are assumed to
satisfy the appropriate inf-sup condition that render the standard Galerkin
method stable, and another augmented and stabilised one that permits the use of
finite element interpolations of arbitrary order. Stability and convergence
results are provided for the two finite element formulations considered
Assessment of Austrian contribution toward EU 2020 target sharing: Responding to the energy and climate package of the European Commission
The overarching implications of the EU 2020 targets for Austria call for a fundamental restructuring of the Austrian energy sector towards increased energy efficiency. Two guiding principles for this restructuring are required in order to be compatible with the targets for greenhouse gas emissions and renewables (RES) expected for Austria: final energy consumption needs to be stabilised at the levels of 2005; renewable energy sources need to be expanded at least by 40 percent. For the final negotiations on phase 3 of the EU Emissions Trading System we propose contributions on three issues: 1. operational procedures for dealing with carbon leakage and competitiveness in all sectors that provide criteria for allocating free allowances: 2. empowering the carbon market by extending the task of the emissions allowances issuing carbon authority to control the liquidity of the carbon market in view of stabilising the carbon price; 3. designing the auctioning mechanism by considering timing and auctioning as a strategic instrument for enhancing the carbon market and considering unified auc-tioning with revenues split among EU countries. Similarly we suggest for the final negotiations on the RES Directive improvements that overcome discrepancies between national RES targets and available resources for implementation. This requires in particular improved cooperation between EU countries for a better mapping of targets and potentials
Aggravation of cold-induced injury in Vero-B4 cells by RPMI 1640 medium – Identification of the responsible medium components
Sr Surface Enrichment in Solid Oxide Cells – Approaching the Limits of EDX Analysis by Multivariate Statistical Analysis and Simulations
In solid oxide cells, Sr segregation has been correlated with degradation. Yet, the atomistic mechanism remains unknown. Here we begin to localize the origin of Sr surface nucleation by combining force field based simulations, energy dispersive X-ray spectroscopy (EDX), and multi-variate statistical analysis. We find increased ion mobility in the complexion between yttria-stabilized zirconia and strontium-doped lanthanum manganite. Furthermore, we developed a robust and automated routine to detect localized nucleation seeds of Sr at the complexion surface. This hints at a mechanism originating at the complexion and requires in-depth studies at the atomistic level, where the developed routine can be beneficial for analyzing large hyperspectral EDX datasets
Effects of clothianidin exposure on sperm quality, testicular apoptosis and fatty acid composition in developing male rats
Clothianidin (CTD) is one of the latest members
of the synthetic organic insecticides, the neonicotinoids.
In the present study, it was aimed to investigate if
daily oral administration of CTD at low doses for
90 days has any deleterious effects on reproductive
functions of developing male rats. Animals were randomly
divided into four groups of six rats each, assigned
as control rats, or rats treated with 2 (CTD-2), 8 (CTD-8)
or 32 (CTD-32) mg CTD/kg body weight by oral gavage.
The significant decreases of the absolute weights
of right cauda epididymis and seminal vesicles, and
body weight were detected in the animals exposed to
CTD administration at 32 mg/kgBW/day. Epididymal
sperm concentration decreased significantly in CTD-32
group and the abnormal sperm rates increased in CTD-
8 and CTD-32 groups when compared to control group.
The testosterone level was significantly decreased in
CTD-32 group when compared to control group. The
administration of all CTD doses resulted in a significant
decrease in the level of GSH. The number of TUNELpositive
cells significantly increased in the germinal
epithelium of testis of rats exposed to CTD at
32 mg/kgBW/day. In groups CTD-8 and CTD-32,
only docosapentaenoic, arachidonic, palmitic and palmitoleic
acids were significantly elevated when compared
to control. The ratios of 20:4/18:2 and 18:1n−9/
18:0 were decreased when rats exposed to CTD. Sperm
DNA fragmentation was observed in CTD-32 group,
but not CTD-2 and CTD-8. It is concluded that low
doses of CTD exposure during critical stages of sexual maturation had moderate detrimental effects on reproductive
organ system and more severe effects are likely
to be observed at higher dose levels. In addition, the
reproductive system may be more sensitive to exposure
of CTD even earlier in development (prenatal and early
postnatal), and therefore it could be expected that more
severe effects could also be observed at the NOAEL
dose levels, if dosing had occurred in utero or early
postnatal
Insecticide imidacloprid induces morphological and DNA damage through oxidative toxicity on the reproductive organs of developing male rats
We investigated whether treatment with imidacloprid would induce morphological changes, DNA fragmentation, antioxidant imbalance
and apoptosis in the reproductive system of developing male rats. Twenty-four male rats were included in this 90-day study, starting at 7 days of
age. The rats were divided into four groups. The first group was used as control. The second, third and fourth groups received oral 0.5-, 2- and
8-mg/kg imidacloprid, respectively. Serum, spermand testis sampleswere collected fromall groups at the end of the experimental period. Theweights
of the epididymis, vesicula seminalis, epididymal sperm concentration, body weight gain, testosterone and reduced glutathione values were lower in
the imidacloprid-treated groups than that in the controls. All treated groups had increased lipid peroxidation, fatty acid concentrations and higher rates
of abnormal sperm. Apoptosis and fragmentation of seminal DNA were higher in rats treated at the two higher doses of imidacloprid. These results
show that this compound has a negative effect on sperm and testis of rat
Intra-operative real time intracranial subarachnoid haemorrhage during glial tumour resection: A case report
Glial tumours associated with subarachnoid haemorrhage are very rare. A 64-year-old woman admitted with a history of 3 weeks seizures and a left sided hemiparesis and dysphasia. The magnetic resonance disclosed heterogeneously enhancing a right temporal mass. During surgery, suddenly an abrupt and extensive swelling had occurred both in tumour and the brain tissue. The surgery was completed with a gross total tumour resection together with a partial temporal lobectomy. Postoperative computerized tomography demonstrated a massive subarachnoid hemorrhage (SAH). A cerebral Magnetic Resonance (MR) angiography showed neither an aneurysm nor arteriovenous malformation. Coincidence of an intracerebral tumour and subarachnoid haemorrhage would be devastating
Organometallic iridium(III) anticancer complexes with new mechanisms of action: NCI-60 screening, mitochondrial targeting, and apoptosis
Platinum complexes related to cisplatin, cis-[PtCl2(NH3)2], are successful anticancer drugs; however, other transition metal complexes offer potential for combating cisplatin resistance, decreasing side effects, and widening the spectrum of activity. Organometallic half-sandwich iridium (IrIII) complexes [Ir(Cpx)(XY)Cl]+/0 (Cpx = biphenyltetramethylcyclopentadienyl and XY = phenanthroline (1), bipyridine (2), or phenylpyridine (3)) all hydrolyze rapidly, forming monofunctional G adducts on DNA with additional intercalation of the phenyl substituents on the Cpx ring. In comparison, highly potent complex 4 (Cpx = phenyltetramethylcyclopentadienyl and XY = N,N-dimethylphenylazopyridine) does not hydrolyze. All show higher potency toward A2780 human ovarian cancer cells compared to cisplatin, with 1, 3, and 4 also demonstrating higher potency in the National Cancer Institute (NCI) NCI-60 cell-line screen. Use of the NCI COMPARE algorithm (which predicts mechanisms of action (MoAs) for emerging anticancer compounds by correlating NCI-60 patterns of sensitivity) shows that the MoA of these IrIII complexes has no correlation to cisplatin (or oxaliplatin), with 3 and 4 emerging as particularly novel compounds. Those findings by COMPARE were experimentally probed by transmission electron microscopy (TEM) of A2780 cells exposed to 1, showing mitochondrial swelling and activation of apoptosis after 24 h. Significant changes in mitochondrial membrane polarization were detected by flow cytometry, and the potency of the complexes was enhanced ca. 5× by co-administration with a low concentration (5 μM) of the γ-glutamyl cysteine synthetase inhibitor L-buthionine sulfoximine (L-BSO). These studies reveal potential polypharmacology of organometallic IrIII complexes, with MoA and cell selectivity governed by structural changes in the chelating ligands
Advanced Technologies for Oral Controlled Release: Cyclodextrins for oral controlled release
Cyclodextrins (CDs) are used in oral pharmaceutical formulations, by means of inclusion complexes formation, with the following advantages for the drugs: (1) solubility, dissolution rate, stability and bioavailability enhancement; (2) to modify the drug release site and/or time profile; and (3) to reduce or prevent gastrointestinal side effects and unpleasant smell or taste, to prevent drug-drug or drug-additive interactions, or even to convert oil and liquid drugs into microcrystalline or amorphous powders. A more recent trend focuses on the use of CDs as nanocarriers, a strategy that aims to design versatile delivery systems that can encapsulate drugs with better physicochemical properties for oral delivery. Thus, the aim of this work was to review the applications of the CDs and their hydrophilic derivatives on the solubility enhancement of poorly water soluble drugs in order to increase their dissolution rate and get immediate release, as well as their ability to control (to prolong or to delay) the release of drugs from solid dosage forms, either as complexes with the hydrophilic (e.g. as osmotic pumps) and/ or hydrophobic CDs. New controlled delivery systems based on nanotechonology carriers (nanoparticles and conjugates) have also been reviewed
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