Search results for "Specificity."
showing 10 items of 2232 documents
Assessment of a Modified Acoustic Lens for Electromagnetic Shock Wave Lithotripters in a Swine Model
2013
The acoustic lens of the Modularis electromagnetic shock wave lithotripter (Siemens, Malvern, Pennsylvania) was modified to produce a pressure waveform and focal zone more closely resembling that of the original HM3 device (Dornier Medtech, Wessling, Germany). We assessed the newly designed acoustic lens in vivo in an animal model.Stone fragmentation and tissue injury produced by the original and modified lenses of the Modularis lithotripter were evaluated in a swine model under equivalent acoustic pulse energy (about 45 mJ) at 1 Hz pulse repetition frequency. Stone fragmentation was determined by the weight percent of stone fragments less than 2 mm. To assess tissue injury, shock wave trea…
Age-related and tissue-specific accumulation of oxidative DNA base damage in 7,8-dihydro-8-oxoguanine-DNA glycosylase (Ogg1) deficient mice.
2001
Mutations that influence the repair of oxidative DNA modifications are expected to increase the steady-state (background) levels of these modifications and thus create a mutator phenotype that predisposes to malignant transformation. We have analysed the steady-state levels and repair kinetics of oxidative DNA modifications in cells of homozygous ogg1(-/-) null mice, which are deficient in Ogg1 protein, a DNA repair glycosylase that removes the miscoding base 8-hydroxyguanine (8-oxoG) from the genome. Oxidative purine modifications including 8-oxoG were quantified by means of an alkaline elution assay in combination with Fpg protein, the bacterial functional analogue of Ogg1 protein. In pri…
ChemInform Abstract: Palladium-Catalyzed Skeletal Rearrangement of Spirotricyclic Olefins: A Facile One-Pot Strategy for the Synthesis of a Novel Mot…
2013
The first utilization of acyclic cyclopropane bearing spirocyclic olefines for the generation of stereospecific complex fused ring systems with an achiral catalyst is reported.
Partial purification and some properties of a nucleoside phosphotransferase of chick embryos.
1978
A nucleoside phosphotransferase purified about 40fold from chick embryos utilizes efficiently as phosphate donors deoxyribonucleoside and pyrimidine ribonucleoside monophosphates, whereas the pyrimidine deoxyribonucleoside appear to be the preferred acceptors of phosphate. The enzyme is very unstable to heat, dilution and dialysis. A marked enhancement in the stability is caused by nucleotides and it seems associated with the formation of an aggregated state of the protein.
Determination of ultratrace bismuth in milk samples by atomic fluorescence spectrometry.
2003
Abstract A sensitive procedure was developed for determination of bismuth (Bi) in milk samples by hydride generation atomic fluorescence spectrometry (HG–AFS) after microwave-assisted sample digestion with HNO3 and H2O2. The method provides a sensitivity of 1832 fluorescence units (ng/mL) with a detection limit of 0.01 ng/mL, which corresponds to 20 pg absolute limit of detection, equivalent to 0.50 ng/g in the original sample. Application of the methodology to cow milk samples from the Spanish market showed the presence of Bi at a concentration of 11.8–28.8 ng/g, which compared well with data obtained after dry ashing of samples and with data obtained by inductively coupled plasma–mass spe…
Matrix solid-phase dispersion microextraction and determination by high-performance liquid chromatography with UV detection of pesticide residues in …
1999
A multiresidue method based on matrix solid-phase dispersion (MSPD) microextraction was studied to determine the carbamate, benfuracarb, and urea insecticides, diflubenzuron, flufenoxuron hexaflumuron and hexythiazox, used in control of citrus pests. Optimisation of different parameters, such as the type of solid support for matrix dispersion, elution solvents and the clean-up step were carried out. The method used 0.5 g of orange sample, C8 bonded silica as MSPD sorbent and dichloromethane as eluting solvent. Recoveries, at spiked concentrations below the maximum residue levels established by Spanish Government, were between 74 and 84% with relative standard deviations ranging from 2 to 4%…
Pressurized liquid extraction combined with capillary electrophoresis–mass spectrometry as an improved methodology for the determination of sulfonami…
2007
A new analytical method, based on capillary electrophoresis and tandem mass spectrometry (CE-MS2), is proposed and validated for the identification and simultaneous quantification of 12 sulfonamides (SAs) in pork meat. The studied SAs include sulfathiazole, sulfadiazine, sulfamethoxypyridazine, sulfaguanidine, sulfanilamide, sulfadimethoxyne, sulfapyridine, sulfachloropyridazine, sulfisoxazole, sulfasalazine, sulfabenzamide and sulfadimidine. Different parameters (i.e. separation buffer, sheath liquid, electrospray conditions) were optimized to obtain an adequate CE separation and high MS sensitivity. MS2 experiments using an ion trap as analyzer, operating in the selected reaction monitori…
Absence Ochratoxin A in soy sauce
2004
A method is described for the determination of ochratoxin A (OTA) in soy sauce using phosphate-buffered saline (PBS) extraction, an immunoaffinity clean-up, a liquid chromatographic determination with fluorescence detection (LC-FD) and confirmation with LC-FD after methylation of OTA. Recoveries of OTA spiked to soy sauce samples at 0.25 ng/ml level were 90% with relative standard deviations of 4%. The limit of detection was 0.01 ng/ml for OTA using the proposed method. Furthermore, the proposed method was applied to 60 soy sauce samples from China and Japan and none of them were found to contain OTA.
SPET/CT image co-registration in the abdomen with a simple and cost-effective tool
2002
Fusion of morphology and function has been shown to improve diagnostic accuracy in many clinical circumstances. Taking this into account, a number of instruments combining computed tomography (CT) with positron emission tomography (PET) or single-photon emission tomography (SPET) are appearing on the market. The aim of this study was to evaluate a simple and cost-effective approach to generate fusion images of similar quality. For the evaluation of the proposed approach, patients with neuroendocrine abdominal tumours with liver metastases were chosen, since the exact superimposition in the abdomen is more difficult than in other regions. Five hours following the injection of 110 MBq (111)In…
static optimal estimation of joint accelerations for inverse dynamics problem solution
2002
In inverse dynamics computations, the accuracy of the solution strongly depends on the accuracy of the input data. In particular, estimated joint moments are highly sensitive to uncertainties in acceleration data. The aim of the present work was to improve classical inverse dynamics computations by providing an accurate estimation of accelerations. Accelerations are usually calculated from noise-polluted position data using numerical double differentiation, which amplifies measurement noise. The objective of the present paper is to use all available imperfect position and force measurements to extract optimum acceleration estimations. A weighted least-squares optimisation approach is used t…