Metastable lattice stabilities for the elements

Lattice stabilities for the metastable FCC (Al), BCC (A2) and CPH (A3) allotropes of 43 elements have been evaluated. The results are based on (1) Assessed stable phase data; (2) Phase boundary extrapolations from binary alloy, and elemental pressure-temperature, phase diagrams; (3) A relationship between the entropy of fusion, crystal structure and melting point; (4) Stacking fault energies; (5) Periodic and group trends and (6) First principle electronic energy calculations. Qualitative trends proposed by previous thermochemical evaluations for the transition metals are to a large extent confirmed. However, the evaluated energy differences between the different crystal allotropes are substantially higher and can be closer in magnitude to those predicted by ab-initio electron energy calculations, although particular discrepancies, for example concerning Cr(FCC), still remain. Many of the changes proposed here arise from the reassessment of stable phase data, particularly with respect to recently measured heats of fusion of the high melting point elements.     

Potassium ferrioxalate as a new inexpensive photochemical pyranometer for extensive field work

The feasibility of using a potassium ferioxalate actinometer as a photochemical pyranometer was studied. The preparation, exposure, and spectrophotometric analysis of the pyranometer cell are described. By calibrating it against a Yellot Mark IV solameter, linear correlations were obtained with respect to total insolation and time of exposure. The spectral response, the quantum yields at different wavelengths, the mechanism of photochemical reaction, and the conversion factor for converting the absorption reading into cal/cm²/min are discussed. The advantages of the new pyranometer are its low cost, simplicity of operation and calibration, high sensitivity, and high tolerance to field conditions. It is useful for mapping solar intensity distribution over a wide area.     

氮化硼薄膜的脉冲激光沉积

用Ｑ开关ＹＡＧ激光器的１．０６μｍ的脉冲激光在硅及玻璃衬底上沉积了氮化硼薄膜。做了ＳＥＭ，ＸＲＤ，红外透射谱和紫外一可见透射谱等测试。确认为六方氮化硼（ｈ－ＢＮ）薄膜．并测出其禁带宽度、晶格常数等。     

Measuring individual research productivity: A review and development of the integrated research productivity index.

The purpose of the present study was to investigate methods of measuring individual research productivity for counseling psychologists. Using the 60 members of the Journal of Counseling Psychology editorial board, the authors computed a comparison of 6 popular indices of productivity, revealing considerable levels of positive skewness, kurtosis, and overlap with each other. Combining the strengths of the 6 indices, the authors developed a new productivity index entitled the Integrated Research Productivity Index (IRPI). The IRPI measures individual productivity by statistically combining an individual's author-weighted publications, average times cited by other publications, and years since first publication into a comprehensive score. Productivity values and IRPI scores for 3 groups of counseling psychologists (Tyler Award recipients, Kuder Award recipients, and Division 17 Presidents) were computed to provide evidence of discriminant validity among the indices. In contrast to the other measures examined, the IRPI accounts for productivity per year and years in the field and assesses mean citation count per article as opposed to total citation count, thus yielding similar scores for Tyler (lifetime) and Kuder (early career) research award recipients. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reaction and total cross sections for low energy pi + and pi - on isospin zero nuclei

We calculated the electrostatic force between a planar interface, such as a planar-supported lipid bilayer membrane, and the tip of a stylus on which another lipid bilayer or some other biomacromolecular system might be deposited. We considered styli with rounded tips as well as conical tips. To take into account the effect of dynamical hydrogen-bonded structures in the aqueous phase, we used a theory of nonlocal electrostatics. We used the Derjaguin approximation and identified the systems for which its use is valid. We pointed out where our approach differs from previous calculations and to what extent the latter are inadequate. We found that 1) the nonlocal interactions have significant effects over distances of 10-15 A from the polar zone and that, at the surface of this zone, the effect on the calculated force can be some orders of magnitude; 2) the lipid dipoles and charges are located a distance L from the hydrophobic layer in the aqueous medium and this can have consequences that may not be appreciated if it is ignored; 3) dipoles, located in the aqueous region, can give rise to forces even though the polar layer is unchanged, and if this is ignored the interpretation of force data can be erroneous if an attempt is made to rationalize an observed force with a knowledge of an uncharged surface; 4) the shape of the stylus tip can be very important, and a failure to take this into account can result in incorrect conclusions, a point made by other workers; and 5) when L is nonzero, the presence of charges and dipoles can yield a force that can be nonmonotonic as a function of ionic concentration.     

Condom Use Among High-Risk Adolescents: Testing the Influence of Alcohol Use on the Relationship of Cognitive Correlates of Behavior.

The goal of this study was the exploration of distal effects of alcohol use on condom use. Criminally involved adolescents completed an initial measure of attitudes, beliefs, and prior behavior. Of the 300 who completed the initial measurement, 267 (89%) completed a behavioral assessment 6 months later. Analyses validated a theoretical model of condom use intentions and indicated that intentions and attitudes measured at baseline were significant predictors of condom use behavior 6 months later. Neither alcohol use nor alcohol problems moderated relationships among model variables or the influence of intentions and attitudes on behavior. The findings do not support a distal role for alcohol use in altering the cognitive correlates of condom use intentions and behavior among high-risk adolescents. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Prefrontal control of trace versus delay eyeblink conditioning: Role of the unconditioned stimulus in rabbits (Oryctolagus cuniculus).

The conditioned eyeblink (EB) response was studied with trace conditioning procedures in rabbits (Oryctolagus cuniculus) with lesions to the medial prefrontal cortex (mPFC) or sham lesions. Three experiments were performed in which either periorbital shock or a corneal airpuff served as the unconditioned stimulus (US) in separate groups of sham or mPFC-lesioned rabbits. Acquisition of the EB conditioned response (CR) was faster and reached a higher asymptote with the eyeshock US than with the airpuff US. However, mPFC lesion-induced trace conditioning deficits were obtained only in the groups that received the airpuff US. All rabbits showed normal delay conditioning and extinction. These results suggest that mPFC mediates trace EB conditioning when emotional arousal is low. However, in circumstances when emotional arousal may be high (i.e., during exposure to aversive periorbital shock), other structures (such as amygdala) may be activated to permit learning even in the absence of input from mPFC. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sugar-induced molten-globule model

Proteins denature at low pH because of intramolecular electrostatic repulsions. The addition of salt partially overcomes this repulsion for some proteins, yielding a collapsed conformation called the A-state. A-states have characteristics expected for the molten globule, a notional kinetic protein folding intermediate. Here we show that the addition of neutral sugars to solutions of acid-denatured equine ferricytochrome c induces formation of the A-state in the absence of added salt. We characterized the structure and stability of the sugar-induced A-state with circular dichroism spectropolarimetry (CD) and NMR-monitored hydrogen-deuterium exchange experiments. We also examined the stability of the sugar-induced A-state as a function of sugar size and concentration. The results are interpreted using several models and we conclude that the stabilizing effect is consistent with increased steric repulsion between the protein and the sugar solutions.     

A novel cyclic adenosine monophosphate analog induces hypercalcemia via production of 1,25-dihydroxyvitamin D in patients with solid tumors

The treatment of cancer patients with conventional chemotherapy is sometimes associated with severe systemic toxicity and only a minimal survival benefit. Because of this, new less toxic and more efficacious treatments have been sought. 8-Chloro-cAMP (8-Cl-cAMP) is one of a new generation of anticancer drugs that act at the level of signal transduction. In preclinical models, 8-Cl-cAMP modulates protein kinase A (PKA) leading to growth inhibition and increased differentiation of cancer cells. 8-Cl-cAMP was given to 16 patients with advanced cancer as an infusion via an indwelling subclavian venous catheter. We showed that 8-Cl-cAMP had a parathyroid hormone-like effect leading to increased synthesis of renal 1,25-dihydroxyvitamin D [up to 14 times the baseline value, median 3.6 times; P = 0.00001 (Student's paired t test)]. This produced the dose-limiting toxicity of reversible hypercalcemia that could not be controlled by the administration of either pamidronate or dexamethasone. The treatment was otherwise well tolerated, and other cAMP-dependent pathways (cortisol and TSH) were not affected, emphasizing the marked differences between organs in their sensitivity to this cAMP analog. Our results have shown that 8-Cl-cAMP is biologically active, and it is feasible that if the hypercalcemia can be controlled, then this drug may have a role as a single agent, or as a short infusion between cycles of chemotherapy.