PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 15769021

[Experimental study on laser-induced plasma and its application to spectral analysis].

Shu-rui Zhao·Jin-zhong Chen·Yan-hong Wei·Qing-lin Guo
View original source ↗Export metadata ↓

Abstract

The article summarizes the progress in the experimental study on laser-induced plasma and its application to spectral analysis domestically and abroad in recent years. It emphatically elaborates the experimental research on the formation, radiation, electron temperature, electron density, and expansion velocity of laser-induced plasma under different conditions (gas composition and pressure, laser energy, laser wavelength, power density and observation height). In addition, in the respect of material composition analysis using the laser-induced plasma, the article mainly interprets two aspects: one is the way to collect directly the plasma emission so as to analyze solid, liquid and gaseous samples, the other is the spectrochemical analysis when laser ablation and ICP are used together. And the article also discusses the factors that influence the precision and the limit of detection.

Explore related subjects

Clinical Laboratory TechniquesEquipment DesignGasesLasersLasers, Solid-StateLimit of DetectionPressureResearchScattering, RadiationSurface Plasmon ResonanceSurface PropertiesEnglish AbstractJournal Article

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Shu-rui Zhao, Jin-zhong Chen, Yan-hong Wei, Qing-lin Guo. 2004. [Experimental study on laser-induced plasma and its application to spectral analysis].. https://pubmed.ncbi.nlm.nih.gov/15769021/

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2007

Effect of temperature on the extraction kinetics and diffusivity of Cyclosporin A in the fungus Tolypocladium inflatum.

The influence of temperature on the extraction kinetics of Cyclosporin A (CyA) from the mycelia of Tolypocladium inflatum was examined in this study. The extraction of CyA from mycelia was performed in a 2-L stirred, baffled vessel using 30% v/v aqueous methanol. The temperature range used was from 5 to 45 degrees C. A linear relationship was found between the extraction yield of CyA and temperature. As the temperature increased, the yield of CyA increased with a maximum CyA yield of 18.3% obtained at 45 degrees C, which is 21.3% higher than the yield at 25 degrees C. The activation energy for the extraction of CyA from T. inflatum was found to be 36.7 kJ/mol, which indicates that the extraction of CyA from T. inflatum is controlled by both solubilization of CyA and diffusion of CyA through the solid phase of mycelia. The overall mass transfer coefficient, k(L)a(S), was found to increase from 1.02 x 10(-3) to 1.34 x 10(-2) s(-1) as the temperature increased from 5 to 45 degrees C. The effective diffusivity of CyA in the solid matrix of mycelia was found to increase from 1.05 x 10(-15) to 1.43 x 10(-14) m(2)/s as the temperature increased from 5 to 45 degrees C. A mathematical diffusion model was developed and was used to fit the experimental kinetic data of CyA extraction and determination of CyA effective diffusivities at different temperatures. This is the first time CyA diffusivities as a function of extraction temperature are reported in the literature.

Clinical Laboratory Techniques↗
PubMed2007

Laboratory-confirmed non-O157 Shiga toxin-producing Escherichia coli--Connecticut, 2000-2005.

Shiga toxin-producing Escherichia coli (STEC) infection causes diarrhea that is often bloody and can result in potentially life-threatening hemolytic uremic syndrome (HUS). Escherichia coli O157:H7 is the most common cause of STEC infection in the United States, producing 73,000 illnesses annually, according to the last estimate in 1999. Unlike O157, however, little is known about the incidence of non-O157 strains. Because STEC other than O157 are not commonly identified, the incidence, trends, and epidemiology of non-O157 STEC are not well understood. To assess trends in Shiga toxin enzyme immunoassay (Stx EIA) testing by local clinical laboratories, the Connecticut Department of Public Health (CTDPH) analyzed results of confirmatory testing conducted in the state laboratory during 2000--2005. The findings indicated that a total of 403 STEC infections were reported by clinical laboratories in Connecticut, including 207 identified as STEC by Stx EIA testing alone, and that the use of Stx EIA increased from 2000 to 2005. Use of Stx EIA without prompt culture confirmation can delay or prevent serotyping and subtyping of isolates and detection of both O157 and non-O157 STEC outbreaks. Public health authorities in all states should ensure that clinical laboratories forward Stx EIA-positive specimens to the state laboratory for isolation and identification of STEC, as recommended by the Association of Public Health Laboratories and CDC.

Clinical Laboratory Techniques↗
PubMed2007

Clinical use of laboratory tests for the identification of secondary forms of arterial hypertension.

The prevalence of secondary hypertension can be underestimated if appropriate tests are not performed. The importance of selecting patients with a high pre-test probability of secondary forms of hypertension is first discussed. The laboratory tests currently used for seeking a cause of hypertension are critically reviewed, with emphasis on their operative features and limitations. Strategies to identify primary aldosteronism, the most frequent form of secondary hypertension, and to determine its unilateral or bilateral causes are described. Treatment entails adrenalectomy in unilateral forms, and mineralocorticoid receptor blockade in bilateral forms. Renovascular hypertension is also a common, curable form of hypertension, that should be identified as early as possible to avoid the onset of cardiovascular target organ damage. The tests for its confirmation or exclusion are discussed. The various tests available for the diagnosis of pheochromocytoma, which is much rarer than the above but extremely important to identify, are also described, with emphasis on recent developments in genetic testing. Finally, the tests for diagnosing some rarer monogenic forms and other renal and endocrine causes of arterial hypertension are explored.

Clinical Laboratory Techniques↗