C7-Derivatization of C3-Alkylindoles Including Tryptophans and Tryptamines

A versatile strategy for C7-selective boronation of tryptophans, tryptamines, and 3-alkylindoles by way of a single-pot C2/C7-diboronation–C2-protodeboronation sequence is described. The combination of a mild iridium-catalyzed C2/C7-diboronation followed by an in situ palladium-catalyzed C2-protodeboronation allows efficient entry to valuable C7-boroindoles that enable further C7-derivatization. The versatility of the chemistry is highlighted by the gram-scale synthesis of C7-boronated N-Boc-L-tryptophan methyl ester and the rapid synthesis of C7-halo, C7-hydroxy, and C7-aryl tryptophan derivatives.National Institute of General Medical Sciences (U.S.) (GM089732)National Institute of General Medical Sciences (U.S.) (GM074825)National Science Foundation (U.S.) (CHE-1205646

Antibiotic resistance genes in treated wastewater and in the receiving water bodies: a pan-European survey of urban settings

There is increasing public concern regarding the fate of antibiotic resistance genes (ARGs) during wastewater treatment, their persistence during the treatment process and their potential impacts on the receiving water bodies. In this study, we used quantitative PCR (qPCR) to determine the abundance of nine ARGs and a class 1 integron associated integrase gene in 16 wastewater treatment plant (WWTP) effluents from ten different European countries. In order to assess the impact on the receiving water bodies, gene abundances in the latter were also analysed. Six out of the nine ARGs analysed were detected in all effluent and river water samples. Among the quantified genes, intI1 and sul1 were the most abundant. Our results demonstrate that European WWTP contribute to the enrichment of the resistome in the receiving water bodies with the particular impact being dependent on the effluent load and local hydrological conditions. The ARGs concentrations in WWTP effluents were found to be inversely correlated to the number of implemented biological treatment steps, indicating a possible option for WWTP management. Furthermore, this study has identified bla as a possible resistance gene for future studies investigating the impact of WWTPs on their receiving water. [Abstract copyright: Copyright © 2019 The Authors. Published by Elsevier Ltd.. All rights reserved.

Enzyme‐assisted aqueous extraction of Kalahari melon seed oil: optimization using response surface methodology

Enzymatic extraction of oil from Kalahari melon seeds was investigated and evaluated by response surface methodology (RSM). Two commercial protease enzyme products were used separately: Neutrase® 0.8 L and Flavourzyme® 1000 L from Novozymes (Bagsvaerd, Denmark). RSM was applied to model and optimize the reaction conditions namely concentration of enzyme (20–50 g kg−1 of seed mass), initial pH of mixture (pH 5–9), incubation temperature (40–60 °C), and incubation time (12–36 h). Well fitting models were successfully established for both enzymes: Neutrase 0.8 L (R 2 = 0.9410) and Flavourzyme 1000 L (R 2 = 0.9574) through multiple linear regressions with backward elimination. Incubation time was the most significant reaction factor on oil yield for both enzymes. The optimal conditions for Neutrase 0.8 L were: an enzyme concentration of 25 g kg−1, an initial pH of 7, a temperature at 58 °C and an incubation time of 31 h with constant shaking at 100 rpm. Centrifuging the mixture at 8,000g for 20 min separated the oil with a recovery of 68.58 ± 3.39%. The optimal conditions for Flavourzyme 1000 L were enzyme concentration of 21 g kg−1, initial pH of 6, temperature at 50 °C and incubation time of 36 h. These optimum conditions yielded a 71.55 ± 1.28% oil recovery

A cross-national mixed-method study of reality pedagogy

This mixed-methods cross-national study investigated the effectiveness of reality pedagogy (an approach in which teachers become part of students’ activities, practices and rituals) in terms of changes in student perceptions of their learning environment and attitudes towards science. A questionnaire was administered to 142 students in grades 8–10 in the Bronx, New York City and Dresden, Germany. The questionnaire combines learning environment scales from the Constructivist Learning Environment Survey and the What Is Happening In this Class? Questionnaire with attitude scales from the Test of Science-Related Attitudes. Student interviews were used to support questionnaire findings. Quantitative data analyses revealed that reality pedagogy had a greater impact on students in the Bronx than in Dresden, with qualitative data clarifying differences in how reality pedagogy was enacted in each geographic area. Overall, our findings add to the body of evidence concerning the effectiveness of reality pedagogy as an approach to teaching and learning science across a variety of contexts. © 2016 Springer Science+Business Media Dordrech

ultrasound pre-treatment application

Effect of ultrasound application prior to hot air drying on drying and rehydration kinetics, rehydration ratio and microstructure of okra slices were investigated. For this purpose, the selected parameters are ultrasound pre-treatment time (10, 20 and 30 min), ultrasound amplitude (55 and 100%) and the temperature of drying air (60 and 70 A degrees C). 5 mm thick cylindrical shaped okra slices were used in the experiments. The samples were immersed in water and ultrasonic pre-treatments were done in water with ultrasonic probe connected to an ultrasonic generator with 20 kHz frequency. Pre-treated samples were dried in a tray drier with a 0.3 m/s air velocity. Ultrasound pre-treatment affected the drying rate of the okra slices significantly. Drying time of okra slices was decreased by the application of ultrasound pre-treatment. Modified Page model found to be the most suitable model for describing the drying characteristics of okra slices. Improvements in rehydration properties of the dried samples were observed due to the ultrasound pre-treatment. The influence of the ultrasound pre-treatment on microstructure was clearly observed through scanning electron microscopy images of the dried samples. As the amplitude of ultrasound increased the changes in structure of the okra tissue increased

APPLICATION OF ULTRASOUND IN FOOD DRYING

Drying has a privileged position in all food preservation methods by reducing of existing water content in food not allowing spoilage, providing a precise and cheap preservation opportunity. Sound waves with frequencies above human hearing are called as ultrasound. Ultrasound which is applied prior to drying as pretreatment or simultaneously is effective on drying performance of products. It is known that diffusion of water increased and total process time shortened in processes that ultrasonic energy is combined with different drying methods and products treated with ultrasound are rehydrated easier. Also ultrasound found to be an alternative method for producing low-sugar dried products. In this study, the basic effect mechanisms of ultrasonic energy and its application fields, effect on drying kinetics and products quality in processes which ultrasound combined with different drying methods such as osmotic drying, hot air drying and freeze drying are examined in the light of studies in literature

Role of apoptosis, bcl-2 and bax protein expression in premature rupture of fetal membranes

WOS: 000178826800002PubMed ID: 12418062OBJECTIVE: To examine the degree of apoptosis in human fetal membranes associated with premature rupture Of membranes (PROM) as compared with normal pregnancies and to evaluate the expression of proapoptotic bax and antiapoptotic bcl-2 gene products. STUDY DESIGN: Fetal membranes from 50 pregnancies were included in the study. Thirty of 50 pregnancies had PROM. Twenty pregnancies with intact membranes served as controls. Chorioamniotic membrane biopsies were taken from the rupture site of the membrane and periphery of the rupture side. In the control group, membrane biopsies were taken from the artificial rupture site, cervical pole of the membranes and, membranes close to the edge of the placenta. In recognizing apoptotic figures, routinely processed samples were stained with hematoxylin and eosin for light microscopic evaluation. Quantification of the apoptotic cells was performed with high-power fields and expressed as the number per 100 cells. The membranes of both groups were then stained with bcl-2 and bax antibodies by using the standard steptavidin-biotin-immunoperoxidase method. Staining with both antibodies were compared between two groups. RESULTS: Apoptotic cells were detected in the amniotic epithelium, in chorionic cells and fibroblastic layer of the fetal membranes. Apoptotic cells were found mostly in the chorionic cells. There was a statistically significant difference between the apoptotic index in PROM and the control group in both rupture and peripheral sites (P<.05), although within each group peripheral and rupture sites showed no difference in terms of apoptotic cell counts. Both bax and bcl-2 expression was observed in 40% of control cases and in 57% and 50% of cases with PROM, respectively, mostly in the chorionic trophoblastic cells. The PROM and control groups showed no statistically significant difference in terms of bcl-2 and bax protein expression. CONCLUSION: Apoptosis may play a role in the pathogenesis of PROM, but the changes in apoptosis do not seem to be mediated by bcl-2 and bax genes in the amniotic membrane. Other regulatory mechanisms must be investigated