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Differential Method (differential + method)
Selected AbstractsSynthesis of 1-amino-2-methylindoline by Raschig process: Parallel reactions, modeling, and optimizationINTERNATIONAL JOURNAL OF CHEMICAL KINETICS, Issue 10 2002M. Elkhatib The reaction between chloramine and 2-methylindoline was studied at pH 12.89, T = 40°C, and for different initial concentrations of reactants. The interaction includes two concurrent bimolecular mechanisms leading to 1-amino-2-methylindoline and 2-methylindole. The rate laws were determined at the first moments of the reaction by using a differential method. By considering the totality of the reactions that occur in the medium, an appropriate mathematical model was developed. It permits to follow the evolution of the system over time and to calculate the final yields of reaction products. An optimization in terms of the initial contents of 2-methylindoline and chloramine was performed. It indicated that the maximum yield of 1-amino-2-methylindoline does not exceed 56%. The results show the limit of the Raschig process for the synthesis of indolic hydrazines in aqueous medium. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 34: 575,584, 2002 [source] Detection and survival of Campylobacter in chicken eggsJOURNAL OF APPLIED MICROBIOLOGY, Issue 5 2003O. Sahin Abstract Aims:Campylobacter jejuni, a food-borne human pathogen, is widespread in poultry; however, the sources of infection and modes of transmission of this organism on chicken farms are not well understood. The objective of this study was to determine if vertical transmission of C. jejuni occurs via eggs. Methods and Results: Using a temperature differential method, it was shown that Campylobacter had limited ability to penetrate the eggshell. When C. jejuni was directly inoculated into the egg yolk and the eggs were stored at 18°C, the organism was able to survive for up to 14 days. However, viability of C. jejuni was dramatically shortened when injected into the albumen or the air sac. When freshly laid eggs from Campylobacter -inoculated specific pathogen-free (SPF) layers were tested, C. jejuni -contamination was detected in three of 65 pooled whole eggs (5,10 eggs in each pool) via culture and PCR. However, the organism was not detected from any of the 800 eggs (80 pools), collected from the same SPF flock, but kept at 18°C for 7 days before testing. Likewise, Campylobacter was not recovered from any of 500 fresh eggs obtained from commercial broiler-breeder flocks that were actively shedding Campylobacter in faeces. Also, none of the 1000 eggs from broiler breeders obtained from a commercial hatchery were positive for Campylobacter. Conclusions: These results suggest that vertical transmission of C. jejuni through the egg is probably a rare event and does not play a major role in the introduction of Campylobacter to chicken flocks. Significance and Impact of the Study: Control of Campylobacter transmission to chicken flocks should focus on sources of infection that are not related to eggs. [source] Optimization of hot water extraction of roselle juice using response surface methodology: a comparative study with other extraction methodsJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 12 2003Peng-Kong Wong Abstract Roselle has regained the attention of many fruit juice manufacturers in Malaysia as a product that contains high ascorbic acid and anthocyanins. However, ascorbic acid and anthocyanin pigments can be easily destroyed during processing of fruit juice. Therefore, in the present study, the effects of different processing methods, namely hot water extraction (HWE), hot water blending, cold water blending and screw press, on the changes in anthocyanins and ascorbic acid contents of roselle juice were evaluated. The anthocyanins and ascorbic acid contents of roselle were determined using the pH differential method and high-performance liquid chromatography respectively. The physico-chemical characteristics and sensory properties of roselle juice were also evaluated. The results of the study indicate that the HWE method is the most effective extraction method, resulting in high anthocyanins and ascorbic acid contents of 43 g l,1 (as delphinidin-3-glucoside) and 2.34 g kg,1 respectively. The optimum juice extraction conditions were 3.5 h at 60 °C. Copyright © 2003 Society of Chemical Industry [source] Knowledge and impressions regarding the concept of mutation among Japanese university studentsCLINICAL GENETICS, Issue 1 2008N Ando Although the term mutation is frequently used in genetic counseling, it may carry negative connotations and create misunderstanding. Our objective was to investigate the relationship between the impressions regarding three Japanese terms mutation of gene, change of gene, and lesion of gene as well as to investigate the depth of understanding regarding mutation. A total of 175 university students and auditing students were included and responded to two questionnaires that were Impressions regarding the term in the semantic differential method and Knowledge about the concept of mutation. In factor analysis, three factors (Value, Change Rate, and Intention) were extracted. Participants were divided into three groups depending on their knowledge, and a two-way analysis of variance (Term × Knowledge Group) was conducted on the factor score for each. Results showed that the main effect of the ,Term' was significant for the Value Factor and that interaction was significant for the Change Rate Factor, and that the main effect of Knowledge Group was significant for the Intention Factor. The findings suggest that healthcare professionals should demonstrate an awareness of varying impressions of the different terms used to refer to the identical concepts of mutation. This is of particular importance when communicating with patients and their families. [source] | |||||||||||||