Catalyst development for the selective methylation of catechol

Gas-phase alkylation of catechol with methanol on g-alumina and modified g-alumina catalysts is studied exptl. By limiting the conversion of X < 0.3, the formation of polymethylated species can be avoided and only the three isomers guaiacol, 3-methylcatechol and 4-methylcatechol are obsd. Optimizing the catalyst compn. and the reaction conditions, a selectivity of 0.75 for the industrially most valuable product 3-methylcatechol can be obtained. [on SciFinder (R)

Viscosity solutions of systems of PDEs with interconnected obstacles and Multi modes switching problems

This paper deals with existence and uniqueness, in viscosity sense, of a solution for a system of m variational partial differential inequalities with inter-connected obstacles. A particular case of this system is the deterministic version of the Verification Theorem of the Markovian optimal m-states switching problem. The switching cost functions are arbitrary. This problem is connected with the valuation of a power plant in the energy market. The main tool is the notion of systems of reflected BSDEs with oblique reflection.Comment: 36 page

Size-associated Variation and Factors Affecting the Morphology of Brown Bodies in Glycera tridactyla (Polychaeta:Glyceridae)

Size-associated variations in brown body morphology (size and shape) were studied from the individuals of Glycera tridactyla. Variables related to size, length (BL) and width (BW) of the brown bodies were measured. On the basis of these measurements, other variables such as the surface area (SA), volume (V), surface area/volume ratio (SA/V) and elongation degree (ED) were calculated. Brown body shape was quantified by the elongation degree. The immature brown bodies were significantly smaller than the mature bodies, and therefore the smaller bodies had a higher SA/V. Results obtained from the regression analysis showed that there was a significant relationship between all the variables with the exception of SA/V:BW for the immature bodies and ED: BL for both groups of the bodies. The body size (proboscis length) of the worm and the sampling time (months) were the affecting factors on size and shape of the brown body. Brown bodies tend to be elongated as the proboscis length increased. The variation in size and/or shape of the brown bodies could refer to an adaptation to the movement along the coelomic fluid

Nicotine enhances an auditory Event-Related Potential component which is inversely related to habituation

Nicotine is a psychoactive substance that is commonly consumed in the context of music. However, the reason why music and nicotine are coconsumed is uncertain. One possibility is that nicotine affects cognitive processes relevant to aspects of music appreciation in a beneficial way. Here we investigated this possibility using Event-Related Potentials (ERPs). Participants underwent a simple decision-making task (to maintain attentional focus), responses to which were signaled by auditory stimuli. Unlike most previous research looking at the effects of nicotine on auditory processing, we used tones of different pitch, a fundamental element of music. In addition, unlike most other studies, we tested non-smoking subjects to avoid withdrawal-related complications. We found that nicotine (4.0 mg, administered as gum) increased P2 amplitude in the frontal region. Since a decrease in P2 amplitude and latency is related to habituation processes, and an enhanced ability to disengage from irrelevant stimuli, our findings suggest that nicotine may cause a reduction in habituation, resulting in non-smokers being less able to adapt to repeated stimuli. A corollary of that decrease in adaptation may be that nicotine extends the temporal window during which a listener is able and willing to engage with a piece of music

Creatine and guanidinoacetate reference values in a French population

Creatine and guanidinoacetate are biomarkers of creatine metabolism. Their assays in body fluids may be used for detecting patients with primary creatine deficiency disorders (PCDD), a class of inherited diseases. Their laboratory values in blood and urine may vary with age, requiring that reference normal values are given within the age range. Despite the long known role of creatine for muscle physiology, muscle signs are not necessarily the major complaint expressed by PCDD patients. These disorders drastically affect brain function inducing, in patients, intellectual disability, autistic behavior and other neurological signs (delays in speech and language, epilepsy, ataxia, dystonia and choreoathetosis), being a common feature the drop in brain creatine content. For this reason, screening of PCDD patients has been repeatedly carried out in populations with neurological signs. This report is aimed at providing reference laboratory values and related age ranges found for a large scale population of patients with neurological signs (more than 6 thousand patients) previously serving as a background population for screening French patients with PCDD. These reference laboratory values and age ranges compare rather favorably with literature values for healthy populations. Some differences are also observed, and female participants are discriminated from male participants as regards to urine but not blood values including creatine on creatinine ratio and guanidinoacetate on creatinine ratio values. Such gender differences were previously observed in healthy populations; they might be explained by literature differential effects of testosterone and estrogen in adolescents and adults, and by estrogen effects in prepubertal age on SLC6A8 function. Finally, though they were acquired on a population with neurological signs, the present data might reasonably serve as reference laboratory values in any future medical study exploring abnormalities of creatine metabolism and transport