A simplified method has been developed for agar dilution antimicrobial susceptibility testing of anaerobic bacteria, designed to economize on time and money when only a few isolates need to be tested. The procedure is based on the principle of using filter paper disks as carriers of the antibiotic and 35- by 10-mm petri dishes which, when inoculated with the Steers replicator, can test up to fo...

The blood flows in the common, internal, and external carotid arteries were determined as a percentage of the cardiac output by video dilution technique in 20 normal subjects during routine angiography. Nine women and 11 men, ages 19-63 years, displayed a mean flow in the common carotid of 8.5% (SD +/- 0.9%; n = 40); internal carotid, 5.3% (SD +/- 1.0%; n = 24); and external carotid, 3.2% (SD +...

Physical and chemical processes related to primary production of the estuaries two rivers with different water regime are considered special attention their spatial seasonal variability. Both degradation organic matter quantitatively evaluated on data non-conservative variation dissolved inorganic phosphorus concentration in process river dilution. Contribution recycling balance estuarine water...

The isotope dilution mass spectrometry (IDMS) is a highly efficient method for tackling the ion suppression in complex matrix by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), but a lack of commercial internal standards is a limiting factor for these analyses. Herein, an economical and efficient strategy for the synthesis of (13)C3-simazine via a three-step proce...

BACKGROUND Determination of vancomycin minimum inhibitory concentration (MIC) can influence the agent used to treat methicillin-resistant Staphylococcus aureus (MRSA) infection. We studied diagnostic accuracy using E-test and VITEK(®) 2 against a gold standard broth microdilution (BMD) methodology, the correlation between methods, and associations between vancomycin MIC and MRSA phenotype from ...

TiO2-coated Ag nanorods (Ag@TiO2 NRs) have been fabricated as multifunctional surface-enhanced Raman scattering (SERS) substrates. Uniform TiO2 shells could sufficiently protect the internal Ag NRs against oxidation and sulfuration, thus the temporal stability of SERS substrates was markedly improved. Meanwhile, due to the synergetic effect between crystalline TiO2 and Ag, the nanocomposites co...

Using dilution plating method, 47 fungal isolates were obtained from a soil sample collected from Dokdo in the East Sea of Korea in 2013. In this study, two fungal isolates, EML-MFS30-1 and EML-DDSF4, were confirmed as undescribed species, Metarhizium guizhouense and Mortierella oligospora in Korea based on current classification system using multi loci including rDNA internal transcribed space...

Combined capillary gas-liquid chromatography-electron capture negative chemical ionization mass spectrometry of pentafluorobenzyl ester-TMSi ether derivatives of bile acids and isotope dilution using deuterated internal standards are introduced as a sensitive and selective analysis technique for plasma bile acids. As a result of the high ionization efficiency of pentafluorobenzyl derivatives un...

A method used to determine Pb in unknown matrices by isotope dilution mass spectrometry (IDMS) was previously published by NIST [1]. IDMS is considered the most accurate method for total blood metals analyses, mainly because it eliminates the blood’s matrix effect [2, 3]. However, the IDMS method is relatively expensive, and cannot be used for mono-isotopic metals such as Mn or As. Alternativel...

An analytical method for the determination of N-nitrosodimethylamine (N-NDMA) in environmental aqueous samples has been developed using isotope dilution gas chromatography/mass spectrometry in the selected ion monitoring mode (GC/MS-SIM). After deuterated N-nitrosodimethylamine (d6-N-NDMA) as surrogate standard was added to the samples, the analytes were extracted with methylene chloride, dried...