Search

A systematic study was performed about the solvolysis reaction of substituted benzoyl chlorides in the presence of zwitterionic vesicles of dipalmitoyl phosphatidylcholine (DPPC). For benzoyl chlorides with electron-donating groups, which react predominantly through a dissociative mechanism, which is strongly affected by medium properties, the rate constant decreases as the vesicle concentration increases.

The chemical behavior of beta-cyclodextrin/nonionic surfactant mixed systems is investigated by using the basic hydrolysis of N-methyl-N-nitroso-p-toluenesulfonamide as a chemical probe. The variations in the hydrophobicity of the surfactant monomer have helped in determining the percentages of uncomplexed cyclodextrin in equilibrium with the micellar system that are in the range of 5-95%.

A study on the reactions of the series of benzoyl chlorides varying the electron-withdrawing character of the substituent in nonionic microemulsion is performed. The study reveals that a variation in the contributions of both reaction pathways associative and dissociative to the whole reaction mechanism and changes in the mechanism can be modulated by modification of the microemulsion composition.

Background and purpose: Although migraine is the second most disabling condition worldwide, there is poor awareness of it. The objective was to assess the awareness of migraine and previous diagnostic and therapeutic consultations and treatments in a large international population of migraineurs. Methods: This was a multicentre study conducted in 12 headache centres in seven countries. Each centre recruited up to 100 patients referred for a first visit and diagnosed with migraine. Subjects were given a structured clinical questionnaire‐based interview about the perceptions of the type of headache they suffered from, its cause, previous diagnoses, investigations and treatments. Results: In all, 1161 patients completed the study. Twenty‐eight per cent of participants were aware that they suffered from migraine. Sixty‐four per cent called their migraine 'headache'; less commonly they used terms such as 'cervical pain' (4%), tension headache (3%) and sinusitis (1%). Eight per cent of general practitioners and 35% of specialists (of whom 51% were neurologists and/or headache specialists) consulted for migraine formulated the correct diagnosis. Before participating in the study, 50% of patients had undergone X‐ray, computed tomography and/or magnetic resonance imaging of the cervical spine and 76% underwent brain and/or cervical spine imaging for migraine. Twenty‐eight per cent of patients had received symptomatic migraine‐specific medications and 29% at least one migraine preventive medication. Conclusions: Although migraine is a very common disease, poor awareness of it amongst patients and physicians is still an issue in several countries. This highlights the importance of the promotion of migraine awareness to reduce its burden and limit direct and indirect costs and the risk of exposure to useless investigations. [ABSTRACT FROM AUTHOR]

Pt catalysts supported on neutral and acid materials, namely SiO2, γ-Al2O3, Na-Beta, and NaH-Beta, were studied in the anisole deoxygenation reaction. The main objective was to compare different supports for this reaction and determine the conditions that maximize the selectivity to deoxygenated products. The reactions were carried out in a fixed-bed reactor at atmospheric pressure by varying the temperature between 200 and 500 °C. Depending on reaction conditions, benzene, and in lesser amounts toluene and xylenes, were obtained as deoxygenated products. Also, n-methylanisoles and n-methylphenols were produced in low amounts. The effects of space time, temperature, and H2/anisole ratio on the catalytic performance were analyzed in a wide range of values, which thus made it possible to obtain detailed information regarding the changes in selectivity and activity upon changes in the operational variables. Anisole deoxygenation to benzene requires both the metallic and the acid functions. Acid and metal sites promoted demethylation needed to allow the deoxygenation reaction to occur. The acid sites also promote transalkylation reactions, which led to undesired oxygenated products, and on the other hand, the acidity catalyzed the alkylation of aromatic rings with the -CH3 fragments coming from demethylation, thus improving the carbon balance. Coke formation follows a series-type mechanism, formed mainly from the anisole. It is possible to regenerate these catalysts by burning the coke with air at 350-400 °C. The catalysts supported on the beta zeolite worked under a mass transfer controlled regime. [ABSTRACT FROM AUTHOR]

Copyright of Motricidad: European Journal of Human Movement is the property of Asociacion Espanola de Ciencias del Deporte and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Barley (Hordeum vulgare L.) production in many regions is constrained by low temperatures. Numerous screening methods have been proposed for studies of freezing tolerance (FT) and 4/inter hardiness (WH), Here, we compared the response to low temperature of 54 barley genotypes released in Europe. Major components of WH were analyzed in field and growth chamber experiments under different hardening and freezing conditions. Phenotype screening of freezing injury (lethal temperature for 50% of the plants [I50], plant survival, and chlorophyll f!uorescence) and indirect evaluations (molecular-marker-based analysis of vernalization requirement) were used. The maximum quanyield of the photosystem II photochemistry measured as the variable (F) to maximal (Fm) fluorescence ratio (Fy:Fm) analysis was confirmed as a reliable method of screening genetic diversity for FT in plants at early growth stages. Variability for FT was also found after shorter acclimation at optimal (3/1°C day/night) or suboptimal (12/7°C day/night) hardening temperatures. High levels of FT and WH were found in both winter and facultative growth habits. Facultative genotypes were more responsive to early hardening than spring or winter types. Some of them coped best with frost in both laboratory and field experiments. The most tolerant winter genotypes coped best with prolonged exposure to low temperature in the field experiments. A conservative estimation of the role of FT in WH implies that at least 50% of WH was associated with the level of FT. A combined analysis using physiological and molecular tools is proposed for phenotyping WH in large populations. [ABSTRACT FROM AUTHOR]

Anecdotally, the fast pace at which the USA men's basketball team played at the 2008 Olympics was the main reason for their dominance, although there is no way of quantifying what a fast pace is or how it contributed to point differentials. The aim of this study was to examine the game-related statistics that discriminate between fast- and slow-paced games, as well as to identify key performance factors relating to point differentials. We analysed game-related statistics for each quarter of the eight games played by the USA using a k-means cluster analysis to classify game pace using ball possessions per game quarter. We then tested for differences in game statistics between slow- and fast-paced game quarters using analysis of variance and discriminant analysis. How differences in game-related statistics affected point differentials was examined using linear regression. The largest structure coefficient between game paces for the USA was for recovered balls (0.33, P < 0.001). The biggest contributors to the point differences in games were recovered balls (16.9, P < 0.001) and field goals (22.2, P < 0.001). We conclude that when the USA play a fast-paced game, they are able to recover more balls from opponents that they then turn into effective field-goal shooting. [ABSTRACT FROM AUTHOR]

A method is explained combining relaxation training, fantasy journey material and a Gestalt technique to achieve an alternative way of carrying out systematic desensitisation. The method is explained in relation to an account of work with a female client experiencing anxiety with birds. This form of programme can successfully avoid the mechanical processes of the behavioural approach, thus giving both the client and the therapist a creative role in the therapeutic process. [ABSTRACT FROM PUBLISHER]

The human teratocarcinoma derived growth factor 1 (TDGF1) gene maps on chromosome (Chr) 3p21.3. One pseudogene (TDGF3) maps on Chr Xq21→q22. We now report the nucleotide sequence and chromosome location of three additional TDGF pseudogenes. The three new sequences (TDGF2, TDGF4 and TDGF5) are truncated at the 5′ end and have accumulated several point mutations, deletions and insertions. TDGF2, TDGF4 and TDGF6 map on Chrs 2q37, 6p25 and 3q22, respectively. Finally, Southern blot analysis of DNA from normal individuals shows a highly variable restriction pattern of the TDGF sequences. [ABSTRACT FROM AUTHOR]

The cryptic ilvlH locus of Salmonella typhimurium has genetic information for two distinct subunits of acetohydroxy acid synthase III. We show that the ilvH-encoded subunit is normally translated and the lack of activity is due to early termination of translation within the promoter-proximal ilvl gene. Analysis of the 5′ region of the operon led to identification of the promoter and the amino-terminal part of ilvl. Expression of this gene in a mutant producing acetohydroxy acid synthase is due to a transversion which creates a UUA (leucine) codon in the place of a UGA (stop) codon present in position 12 of the wild-type coding region. [ABSTRACT FROM AUTHOR]