This study did not support the hypothesis that reduced sensitivity of dopamine receptors is associated with anxiety, depressed mood, or high novelty seeking in alcoholism.

The thermal conductivity of isotopically enriched 28 Si (enrichment better than 99.9%) was redetermined independently in three laboratories by high precision experiments on a total of 4 samples of different shape and degree of isotope enrichment in the range from 5 to 300 K with particular emphasis on the range near room temperature. The results obtained in the different laboratories are in good agreement with each other. They indicate that at room temperature the thermal conductivity of isotopically enriched 28 Si exceeds the thermal conductivity of Si with a natural, unmodified isotope mixture by 10±2 %. This finding is in disagreement with an earlier report by Ruf et al. At ∼26 K the thermal conductivity of 28 Si reaches a maximum. The maximum value depends on sample shape and the degree of isotope enrichment and exceeds the thermal conductivity of natural Si by a factor of ∼8 for a 99.982% 28 Si enriched sample. The thermal conductivity of Si with natural isotope composition is consistently found to be ∼3% lower than the values recommended in the literature. PACS: 66.70.+f, 63.20.Mt, 74.25.Fy, 65.40.Ba, 65.90.+i Keywords: silicon, stable isotopes, thermal conductivity INTRODUCTIONPhonon scattering due to the presence of different isotopes in an otherwise pure crystal (no chemical defects or dislocations) has been identified as a mechanism that strongly affects the thermal conductivity κ [1−3]. The availability of larger quantities of highly isotope-enriched materials recently revived the interest in this effect in order to study the mechanisms underlying the thermal conductivity and possibly to improve material properties [4−8].Recently, the observation of a significantly enhanced thermal conductivity of isotopically enriched 28 Si near room temperature by Capinski [9] and Ruf et al. [10] has generated large interest. In these studies, it was found that the thermal conductivity of isotopically enriched 28 Si is enhanced by about 60% over that of silicon with natural isotopic composition. This rather high isotope effect attracted considerable attention concerning both, fundamental physics and applications. For technical applications, a significantly enlarged thermal conductivity at room 2 temperature would be of interest for high performance electronic devices. [11]. From the fundamental physics aspect, the experimental results were unexpected since the observed isotopic effect was significantly larger than the prediction of simple theoretical estimates [10−13] and more advanced model calculations [14]. On the other hand, theoretical papers [15−17] were published with the results supporting the data of refs. [9,10]. A large isotopic effect at room temperature is in principle only possible if normal phonon-phonon scattering processes play an important role in determining the formation of the non-equilibrium distribution function of phonons at these temperatures.The large room temperature isotope effect was questioned following the results of an experimental study by Gusev et al. [18] which indicate that th...

Staging and score systems may be helpful in calculating prognosis in differentiated thyroid carcinoma, but the benefit of systematic lymphadenectomy remains controversial.

Our study tested the hypothesis of whether the sensitivity of central dopamine receptors corresponds to the genotypic constitution of DNA-polymorphisms of the dopamine D1 and D2 receptor (DRD1, DRD2) genes and is associated with poor treatment outcome. Therefore, 97 alcohol-dependent patients were assessed according to their sensitivity of central dopamine receptors (apomorphine-induced secretion of growth hormone), clinical outcome during a 6-month observation period, and genotypic constitution of the TaqIA restriction fragment length polymorphism (RFLP) at the DRD2 locus and of the Bsp1286I RFLP at the DRD1 locus. On the 1st day of detoxification, dopamine receptor hyposensitivity was found in treatment nonresponders, but not in responders. Apomorphine-induced growth hormone release did not differ significantly in alcoholics with different genotypes of the DRD1 and DRD2 RFLPs. Neither did we find a significant allelic association with treatment response. Thus, we did not find evidence for a genetic determination of dopamine receptor hyposensitivity in alcoholics with poor treatment outcome.

G R~P K. and A. WESTERSTEX. Untersuchungen iiber Eigenschaftcn und Verwendungsmogliclikeiten eines flexiblen Extremitatcnplet.hysmografen. tlcta physiol. scand. 1959. 46. 1--18. -The flexible extremity plethysmographs described by ~O H N were invehgated on a dummy and in situ and found especially suitable for blood flow measurements by means of occlusion plethysmography. The niodels for forearm and calf could be used also on moving subjects, e. y. performing physical work. The plethysniographs consist of thin air-filled rubber cuffs. Volume changes of the extremity caused proportional changes of the filling pressure of the plethysmographs, which at rest was 40 mm H,O and during venous occlusion increased by less than 10 mm H,O. The pressure changes were continuously recorded on a ca.pacitance manometer. Some properties and applications of the plethysmographs are described. Quantitative Durchhlutungsmessungen a n menschlichen Extreinitaten sind his heute in verlasslicher Form iiur m i t der Venenverschlussplethysmografie moglich. Bei der arbeit,enden Versuchsperson wird ihre Anwendung jedoch schwierig. Die bekannten 1 -59.7285. Arta p h y s i o l . scund. Vol. 46.