Qualitative and quantitative analysis of lipid classes in fish oils by thin-layer chromatography with an Iatroscan flame Ionization detector (TLC-FID) and liquid chromatography with an evaporative light scattering detector (LC-ELSD)

Combined effects of hydrogen and air flow rates on the peak response of selected neutral lipid classes (triacylglycerol, diacylglycerol, monoacylglycerol, free fatty acids, and ethyl esters) were studied to optimize and calibrate the Iatroscan Mk-6s Chromarod system for the qualitative and quantitative analysis of lipid classes by thin-layer chromatography (TLC) with flame ionization detection in fish oil during the transesterification process. Air flow rate of 2 L/min, hydrogen flow rate of 150-160 mL/min, and scan rate of 30 s/rod were found to be the optimum conditions. All samples were also analyzed by high performance liquid chromatography (HPLC) with evaporative light scattering detection. Quantitative results obtained by TLC with the flame ionization detection method were comparable to those obtained from HPLC with evaporative light scattering detection.

Qualitative and historiometric methods in leadership research: a review of the first 25 years of the leadership quarterly

In the spirit of the 25th anniversary edition of The Leadership Quarterly, as the world's premier outlet for leadership research, we have reviewed qualitative and historiometric research across those 25. years. Qualitative research is a complex and cluttered area of scholarship. This is not because there is an inherent confusion about it. Rather, it is because 'qualitative' research is a cover-all term for a wide range of research strategies, paradigms, parent disciplines, sources of data, and methods of analysis for them. More so than in previous journal review articles, we explored variation in qualitative analysis as well as variety in qualitative data. In terms of methodologies, our efforts concentrated on case study, content analysis, grounded theory and historiometrics. We also examined trends toward post-positivism, post-modernity and liquid modernity, and their resultant benefits for researching leadership. Future directions for leadership research are posited. © 2013 Elsevier Inc.

Qualitative and quantitative characterization of aluminium alloys after corrosion testing

The 2024 and 7050 aluminium alloys used as aircraft components were subjected to laboratory corrosion tests in sodium chloride solution, Light-microscope examinations make it possible to characterise morphological aspects of the localised corrosion. Image analysis was used to determine both depth and width of pits over corroded surfaces. It has been concluded that the annealing could reduce the pit growth in both alloys, by means of grains recrystallization or recovery. The 2024 alloy also tends to present an exfoliation mechanism, mainly throughout non-recrystallized and recrystallized grain boundaries, increasing the width and sustaining the depth of pit cavities during exposition to saline atmosphere. SEM and EDS analysis reveal the morphology and elemental distribution of the corrosion products formed after immersion corrosion test. Some of these products were identified by X-ray diffraction analysis. For 2024, Al(OH)(3), MS(OH)(2) and Cu2O were found. AI(OH)(3) and Cu2O were also found in 7050 samples.

Birds and bats diverge in the qualitative and quantitative components of seed dispersal of a pioneer tree

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Qualitative and quantitative tear film abnormalities in dogs

Anormalidades do filme lacrimal de cães podem ser classificadas quanto ao seu aspecto quantitativo, qualitativo ou ambos, sendo comumente observada na prática cotidiana. Intercorrências na produção de um ou mais componentes do filme lacrimal ensejam distúrbios oculares em graus variados, denominados ceratoconjuntivite seca. Diversas são as causas da ceratoconjuntivite seca em cães, mas a maioria dos casos é de caráter idiopático, estando associada à participação de linfócitos T. O diagnóstico em medicina veterinária é firmado com base nos valores obtidos pelo teste da lacrimal de Schirmer. O presente artigo objetiva revisar os aspectos relacionados à etiopatogenia e ao diagnóstico da ceratoconjuntivite seca em cães, assim como discutir novas modalidades terapêuticas para a doença.

Ozonized Oils: A qualitative and quantitative analysis

Most of the problems of endodontic origin have a bacterial etiological agent. Thus, there is a continued interest in seeking more effective chemical substances that can replace the camphorated paramonochiorophenol or antibiotics as intracanal medicaments. Among the possible substances, ozone has some interesting biological characteristics: bactericidal action, debriding effect, angiogenesis stimulation capacity and high oxidizing power. The purpose of this study was to chemically evaluate the presence of ozone in sunflower, castor, olive and almond oil, as well as in propylene glycol and byproducts of ozonation, such as formaldehyde. These compounds were ozonized, inserted into empty and sterile vials, and analyzed by testing the reaction between ozone and indigo, for determining the presence of ozone, and subjected to the chromotropic acid test for determining the presence of formaldehyde. It was observed complete absence of ozone in all samples tested and presence of formaldehyde. The bactericidal and healing action of ozonized oils could be attributed to products formed by the ozonation of mineral oils, such as formaldehyde, not to the ozone itself.

Application of headspace solid phase microextraction to qualitative and quantitative analysis of tobacco additives in cigarettes

Cigarettes may contain up to 10% by weight additives which are intended to make them more attractive. A fast and rugged method for a cigarette-screening for additives with medium volatility was developed using automatic headspace solid phase microextraction (HS-SPME) with a 65 microm carbowax-divinylbenzene fiber and gas chromatography-mass spectrometry (GC-MS) with standard electron impact ionisation. In three runs, each cigarette sample was extracted in closed headspace vials using basic, acidic and neutral medium containing 0.5 g NaCl or Na2SO4. Furthermore, the method was optimized for quantitative determination of 17 frequently occurring additives. The practical applicability of the method was demonstrated for cigarettes from 32 brands.

Plant strengtheners enhance parasitoid attraction to herbivore-damaged cotton via qualitative and quantitative changes in induced volatiles

BACKGROUND Herbivore-damaged plants release a blend of volatile organic compounds (VOCs) that differs from undamaged plants. These induced changes are known to attract the natural enemies of the herbivores and therefore are expected to be important determinants of the effectiveness of biological control in agriculture. One way of boosting this phenomenon is the application of plant strengtheners, which has been shown to enhance parasitoid attraction in maize. It is unclear whether this is also the case for other important crops. RESULTS The plant strengtheners BTH [benzo (1,2,3) thiadiazole-7-carbothioic acid S-methyl ester] and laminarin were applied to cotton plants, and the effects on volatile releases and the attraction of three hymenopteran parasitoids, Cotesia marginiventris, Campoletis sonorensis and Microplitis rufiventris, were studied. After treated and untreated plants were induced by real or simulated caterpillar feeding, it was found that BTH treatment increased the attraction of the parasitoids, whereas laminarin had no significant effect. BTH treatment selectively increased the release of two homoterpenes and reduced the emission of indole, the latter of which had been shown to interfere with parasitoid attraction in earlier studies. Canonical variate analyses of the data show that the parasitoid responses were dependent on the quality rather than the quantity of volatile emission in this tritrophic interaction. CONCLUSION Overall, these results strengthen the emerging paradigm that induction of plant defences with chemical elicitors such as BTH could provide a sustainable and environmentally friendly strategy for biological control of pests by enhancing the attractiveness of cultivated plants to natural enemies of insect herbivores. © 2014 Society of Chemical Industry