125 research outputs found
Condensation of Vanillin and Substitution Products with Hippuric Acid (Abstract)
Condensation of vanillin with hippuric acid in presence of acetic anhydride gives a-benzoylamino-3-methoxy-4-acetoxycinnamic acid which, under the conditions of the experiment, loses the elements of water to give the related azlactone. This view of the reaction is supported by the fact that when esters of hippuric acid are used in this condensation lactones are not obtained. The ring may be opened by warming the lactone with 3 N caustic alkali solution. More drastic treatment causes further hydrolysis with the loss of benzoic acid and ammonia, and gives the related pyruvic acid. Similar results were obtained by starting with aceturic instead of hippuric acid. Several substitution products of vanillin were tested
New Halogenated Derivatives of Vanillin
Carles [Bull. Soc., Chim., 17, 14 (1872)] prepared a monoiodovanillin in 1872, but did not prove its structure. Tiemann and Haarmann [Ber., 7, 615 (1874)] obtained a monobromo derivative that was shown by Dakin [Am. Chem. J., 42, 473 (1909)] to have the halogen in position 5 (CHO = 1). Peratoner [ Gazz. Chim. Ital., 28 (1) 235 (1898)] reported a monochloro compound in which the halogen was not oriented, but which may be a 5-derivative. The only dihalogenated vanillin on record is a diiodo compound obtained by Carles, for which no melting point was given, no derivatives prepared, and in which the halogen atoms were not oriented
The Relation of Substituents in the Hydrocarbon Radicals to the Formation and Reactions of Certain Mixed Ethers
Preliminary work in this laboratory indicates that substituents in the ring have an influence on the formation and decomposition of certain mixed ethers. The work now in progress concerns the activating or retarding influence of groups in the para position on the formation and reduction of such ethers. The present work undertakes to compare the activity of 2:nitro:4-chlor phenol and 2:4-dinitro phenol. The methyl and ethyl ethers have been prepared, the ethers from the first being formed in lower yield than from the second. The benzyl ethers were obtained in fair yield from the corresponding potassium salts. The phenyl and allyl ethers of 2:4-dinitro phenol have been prepared and the corresponding derivatives of 2:nitro: 4-chlor phenol will be attempted later. Aluminum amalgam gave a 51% yield of 2:amino: 4-chlor-methyoxy benzene together with a small amount of the azoxy derivative. The methyl, ethyl, and phenyl ethers of 2:4-dinitro phenol have been reduced with ammoniacal hydrogen sulphide and the benzoyl derivatives prepared
Derivation of Benefits from Dislikes in the Advancement via Individual Determination (AVID) College Readiness System
This phenomenological study employed a sequence of three interviews per student to explore the experiences of 20 students in the Advancement via Individual Determination (AVID) college readiness program. Data from recorded interviews was analyzed using categorizing and connecting strategies. Responses indicated that students varied most in their perceptions of the utility of various AVID strategies, but that students recognized they acquired skills that would serve them in the future. Some participants indicated that they disliked specific strategies of the AVID program. Nevertheless, findings showed that students benefitted from strategies, which they stated that they did not enjoy
In Vivo Assessment of Cold Adaptation in Insect Larvae by Magnetic Resonance Imaging and Magnetic Resonance Spectroscopy
Background Temperatures below the freezing point of water and the ensuing ice crystal formation pose serious challenges to cell structure and function. Consequently, species living in seasonally cold environments have evolved a multitude of strategies to reorganize their cellular architecture and metabolism, and the underlying mechanisms are crucial to our understanding of life. In multicellular organisms, and poikilotherm animals in particular, our knowledge about these processes is almost exclusively due to invasive studies, thereby limiting the range of conclusions that can be drawn about intact living systems. Methodology Given that non-destructive techniques like 1H Magnetic Resonance (MR) imaging and spectroscopy have proven useful for in vivo investigations of a wide range of biological systems, we aimed at evaluating their potential to observe cold adaptations in living insect larvae. Specifically, we chose two cold-hardy insect species that frequently serve as cryobiological model systems–the freeze-avoiding gall moth Epiblema scudderiana and the freeze-tolerant gall fly Eurosta solidaginis. Results In vivo MR images were acquired from autumn-collected larvae at temperatures between 0°C and about -70°C and at spatial resolutions down to 27 µm. These images revealed three-dimensional (3D) larval anatomy at a level of detail currently not in reach of other in vivo techniques. Furthermore, they allowed visualization of the 3D distribution of the remaining liquid water and of the endogenous cryoprotectants at subzero temperatures, and temperature-weighted images of these distributions could be derived. Finally, individual fat body cells and their nuclei could be identified in intact frozen Eurosta larvae. Conclusions These findings suggest that high resolution MR techniques provide for interesting methodological options in comparative cryobiological investigations, especially in vivo
“It was Pretty Scary”: The Theme of Fear in Young Adult Women's Descriptions of a History of Adolescent Dating Abuse
The mental health impact of abusive adolescent dating relationships has not been well described, but fear related to abuse has been reported. We elaborate the theme of fear in women's descriptions of a history of adolescent dating abuse. A sample of community-based women, ages 19-34, who experienced an abusive dating relationship during adolescence (ages 11-20) was used. Data were analyzed via thematic analysis. Fear was a consistent and resonant theme. Three types of fear were identified: fear for self, fear for other relationships, and fearful expectation. These results offer important insights into the impact of abusive adolescent relationships on women's mental health
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