Search results for "methods"

A new, easy and safe method for the purification of nucleic acids for reliable PCR

1994

Regional distribution of blood flow in the renal cortex

1969

Es wird ein autoradiographisches Verfahren zur Bestimmung der regionalen Durchblutungsverteilung in differenziert strukturierten Organen beschrieben. Mit dieser neuen Methode wird die Durchblutung der Nierenrinde untersucht. Es wird nachgewiesen, dass die Durchblutungs- bzw. Widerstandsverteilung innerhalb der Rinde nicht einheitlich ist, sondern dass sich drei verschieden durchblutete, anatomisch voneinander abgrenzbare Teile unterscheiden lassen.

An LD50model for predicting psychotropic drug toxicity using biopartitioning micellar chromatography

2001

The LD50 determination is the main way to measure the acute toxicity of all types of substances. At the present time, however, there is increasing opposition to the use of living animals in research and testing activities from animal rights groups as well as some scientists. Nevertheless, the need to have a tool for estimating the potential toxicity of new compounds for human consumption has encouraged the development of alternative methods. Under adequate conditions, the partitioning in micellar liquid chromatography can describe the drug biopartitioning. We have named this chromatographic system biopartitioning micellar chromatography (BMC). In this paper, an LD50 QRAR model developed for…

A two-circuit apparatus for the perfusion of the isolated rat brain.

1973

A perfusion apparatus for the isolated rat brain is described which has two recirculating systems running synchronously. Instantaneous transfer from one circulating system to the other is possible by use of a 2-way stopcock, enabling different media to be perfused through the brain without interrupting the perfusion. The feasibility of the system is demonstrated experimentally.

A new method for the cytochemical demonstration ofp-diphenol: O2 oxidoreductase (laccase)

1971

Nachweis des Enzymsp-Diphenol: O2 oxidoreductase (Laccase) in den Zellen der PilzeAspergillus fumigatus, Aureobasidium pullulans undNeurospora sitophila durch einen Azofarbstoff, der mittels Kupplung des enzymatisch gebildetenp-Chinons mitBesthorn's Hydrazon(3-Methyl-benzthiazolon(2)-hydrazon-hydrochlorid) entsteht. Als Substrat wird Hydrochinon verwendet. Der Farbstoff wird in runden, rotbraunen Granula abgelagert. Kontrollreaktionen bestatigen die Spezifitat der Reaktion.

In vivopredictive release methods for medicated chewing gums

2012

Understanding the performance of a drug product in vivo plays a key role in the development of meaningful in vitro drug release methodology. In case of functional chewing gums, the mode and the mechanism of release and the site of application differ significantly from other conventional solid oral dosage forms and require a special consideration to extract meaningful information from clinical studies. In the current study, suitable drug release methodology was developed to predict the in vivo performance of an investigated chewing gum product. Different parameters of the drug release testing apparatus described in the Ph. Eur. and Pharmeuropa were evaluated. Drug release data indicate that …

Pbca-Type In2O3: The High-Pressure Post-Corundum phase at Room Temperature.

2014

High-pressure powder X-ray diffraction and Raman scattering measurements in cubic bixbyite-type indium oxide (c-In2O3) have been performed at room temperature. On increasing pressure c-In2O3 undergoes a transition to the Rh2O3-II structure but on decreasing pressure Rh2O3-II-type In2O3 undergoes a transition to a previously unknown phase with Pbca space group which is isostructural to Rh2O3-III. On further decrease of pressure, we observed a phase transition to the metastable corundum-type In2O3 near room conditions. Recompression of the metastable corundum-type In2O3 at room temperature leads to a transition to the Rh2O3-III phase, thus showing that the Rh2O3-III phase is the post-corundum…

Phase Stability of Lanthanum Orthovanadate at High Pressure

2016

The journal of physical chemistry / C 120(25), 13749 - 13762(2016). doi:10.1021/acs.jpcc.6b04782

Semi-empirical calculations of the Nb-ion positions in doped crystals

1998

The atomic and electronic structures of Nb impurities in doped perovskite KTaO3 crystals are calculated using the semi-empirical quantum chemical method of the intermediate neglect of the differential overlap (INDO) and a supercell model. When seven Ta ions are replaced by seven Nb ions, the latter clearly demonstrate self-ordering effects which are related to the experimentally observed impurity-induced phase transition. A single Nb impurity reveals an off-centre displacement which is very close to that found in XAFS experiments. The relevant energy gain is very small, approximately 0.0375 eV, which is much smaller than the Nb-clustering energy gain (0.12 eV). These results led us to the c…

Modelling phase transition kinetics of chenodeoxycholic acid with the Runge–Kutta method

2009

Abstract The phase transition kinetics of two chenodeoxycholic acid polymorphic modifications— form I (stable at high temperature), form III (stable at low temperature) and the amorphous phase has been examined under various conditions of temperature and relative humidity. Form III conversion to form I was examined at high temperature conditions and was found to be non-spontaneous, requiring seed crystals for initiation. The formation kinetic model of form I was created incorporating the three-dimensional seed crystal growth, the phase transition rate proportion to the surface area of form I crystals, and the influence of the amorphous phase surface area changes with an empirical stage poin…