The relative permeability of concrete using nitrogen gas

A modified version of a test, originally proposed by BRE (UK), was used to assess relative permeability to nitrogen gas of concretes cured in various ways. Three simple parameters from test plots clearly showed the effects of duration of water curing, followed by drying to constant mass at 50°C; test specimen moisture content was dominant and drying at 105°C reduced differences between concretes of very different quality. Convincing evidence was not found of differences between upper and lower ‘halves’ of cylinders nor between cast and cored ones.     

Electrochemical Characterization of Isolated Nitrogenase Cofactors from Azotobacter vinelandii

The nitrogenase cofactors are structurally and functionally unique in biological chemistry. Despite a substantial amount of spectroscopic characterization of protein-bound and isolated nitrogenase cofactors, electrochemical characterization of these cofactors and their related species is far from complete. Herein we present voltammetric studies of three isolated nitrogenase cofactor species: the iron–molybdenum cofactor (M-cluster), iron–vanadium cofactor (V-cluster), and a homologue to the iron–iron cofactor (L-cluster). We observe two reductive events in the redox profiles of all three cofactors. Of the three, the V-cluster is the most reducing. The reduction potentials of the isolated cofactors are significantly more negative than previously measured values within the molybdenum–iron and vanadium–iron proteins. The outcome of this study provides insight into the importance of the heterometal identity, the overall ligation of the cluster, and the impact of the protein scaffolds on the overall electronic structures of the cofactors.     

Mind-set and close relationships: When bias leads to (in)accurate predictions.

The authors investigated whether mind-set influences the accuracy of relationship predictions. Because people are more biased in their information processing when thinking about implementing an important goal, relationship predictions made in an implemental mind-set were expected to be less accurate than those made in a more impartial deliberative mind-set. In Study 1, open-ended thoughts of students about to leave for university were coded for mind-set. In Study 2, mind-set about a major life goal was assessed using a self-report measure. In Study 3, mind-set was experimentally manipulated. Overall, mind-set interacted with forecasts to predict relationship survival. Forecasts were more accurate in a deliberative mind-set than in an implemental mind-set. This effect was more pronounced for long-term than for short-term relationship survival. Finally, deliberatives were not pessimistic; implementals were unduly optimistic. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Pygmalion revisited: New evidence for student expectancy effects in the classroom.

We conducted a field experiment to test the idea that students' expectations regarding their teacher's competence would influence their classroom behavior and academic achievement. At the end of a 3-week teaching unit, students in two high school classes who had been given an initial positive expectancy about their teacher's ability and motivation engaged in more appropriate and less inappropriate nonverbal behavior and received significantly higher final grades on the unit than did their peers in two no-expectation control classes. We speculate about both the direct (student-mediated) and indirect (teacher-mediated) processes by which students' expectations came to affect their academic outcomes. We also discuss the importance of group-level expectancies and some ethical issues in student expectancy research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

When flattery gets you nowhere: Discounting positive feedback as a relationship maintenance strategy.

Intimates can rely on a number of strategies to protect their relationships from potential threats. In the present article, the authors investigate a new strategy: to discount flattering comments received from an attractive alternative to a dating partner by making a situational attribution. However, the authors did not expect everyone to adopt this strategy, as not everyone is likely sufficiently motivated to override both the tendencies to make dispositional attributions and to accept positive feedback from others. Dating and single participants were informed that an attractive alternative's positive impression of them had been made freely or under constraint. As expected, dating participants in the constraint condition were less likely than were those in the no-constraint condition to believe that the alternative's impression of them was genuine. In contrast, single participants believed that the confederate's impression of them was genuine, irrespective of their experimental condition. Self-esteem further moderated this effect. As hypothesised, only dating participants with low self-esteem were sufficiently motivated to recognise the situational constraint and discount the positive feedback. High self-esteem daters who were less inclined to discount the positive feedback instead protected their relationships by devaluing the alternative's attractiveness compared to singles. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Use of a pharmacophore model for the design of EGF-R tyrosine kinase inhibitors: 4-(phenylamino)pyrazolo[3,4-d]pyrimidines

In the course of the random screening of a pool of CIBA chemicals, the two pyrazolopyrimidines 1 and 2 have been identified as fairly potent inhibitors of the EGF-R tyrosine kinase. Using a pharmacophore model for ATP-competitive inhibitors interacting with the active site of the EGF-R protein tyrosine kinase (PTK), the class of the pyrazolo[3,4-d]pyrimidines was then optimized in an interactive process leading to a series of 4-(phenylamino)-1H-pyrazolo[3,4-d]-pyrimidines as highly potent inhibitors of the EGF-R tyrosine kinase. The most potent compounds 13, 14, 15, 17, 19, 22, 26, 28, and 30 of this series inhibited the EGF-R PTK with IC50 values below 10 nM. High selectivity toward a panel of nonreceptor tyrosine kinases (c-Src, v-Abl and serine/threonine kinases (PKC alpha, CDK1) was observed. In cells, EGF-stimulated cellular tyrosine phosphorylation was inhibited by compounds 13, 15, 19, 22, and 23 at IC50 values below 50 nM, whereas PDGF-induced tyrosine phosphorylation was not affected by concentrations up to 10 microM, thus indicating high selectivity for the inhibition of the ligand-activated EGF-R signal transduction pathway. Compounds 15 and 19 inhibited proliferation of the EGF-dependent MK cell line with IC50 values below 0.5 microM. In addition, two compounds, 9 and 11, showing satisfactory oral bioavailability in mice after oral administration, exhibited good in vivo efficacy at doses of 12.5 and 50 mg/kg in a nude mouse tumor model using xenografts of the EGF-R overexpressing A431 cell line. From SAR studies, a binding mode for 4-(phenylamino)-1H-pyrazolo[3,4-d]pyrimidines, especially for compound 15, at the ATP-binding site of the EGF-R tyrosine kinase is proposed. 4-(Phenylamino)-1H-pyrazolo[3,4-d]pyrimidines represent a new class of highly potent tyrosine kinase inhibitors which preferentially inhibit the EGF-mediated signal transduction pathway and have the potential for further evaluation as anticancer agents.     

Stromal progesterone receptors mediate the inhibitory effects of progesterone on estrogen-induced uterine epithelial cell deoxyribonucleic acid synthesis

The role of epithelial and stromal progesterone (P) receptors (PR) in the regulation of uterine epithelial DNA synthesis by P was investigated by analyzing the four types of tissue recombinants prepared with uterine stroma (S) and epithelium (E) from wild-type (wt) and PR knockout (PRKO) mice: wt-S + wt-E, PRKO-S + PRKO-E, wt-S + PRKO-E, and PRKO-S + wt-E. 17-Beta estradiol (E2) stimulated DNA synthesis in all four types of tissue recombinants. On the other hand, P inhibited E2-induced DNA synthesis only in tissue recombinants prepared with wild-type (PR-positive) stroma (wt-S + wt-E or wt-S + PRKO-E) but not knockout (PR-negative) stroma (PRKO-S + wt-E or PRKO-S + PRKO-E). These results clearly demonstrate that the inhibitory effect of P on uterine epithelial DNA synthesis is mediated by stromal PR. Epithelial PR is neither necessary nor sufficient for P inhibition of E2-induced epithelial DNA synthesis.     

A nonpharmacologic sleep protocol for hospitalized older patients

OBJECTIVES: To evaluate the feasibility of and adherence to a nonpharmacologic sleep protocol targeted to nurses for acutely ill older patients and to test the effectiveness of the protocol on enhancing sleep and reducing sedative-hypnotic drug (SHD) use. DESIGN: Prospective cohort study. SETTING: A 34-bed general medical unit in a university-affiliated teaching hospital. PARTICIPANTS: A total of 175 consecutive admissions aged 70 years or older. INTERVENTION: A nonpharmacologic sleep protocol consisting of a back rub, warm drink, and relaxation tapes was administered by nursing personnel to patients who complained of difficulty initiating sleep or who requested a SHD. After 1 hour, if the patient still requested it, the nurse administered the SHD. MEASUREMENTS: The main outcomes of sleep quality and SHD use were measured by patient interview and chart abstraction. Feasibility and adherence to the protocol were tracked daily by patient and nurse interviews and chart abstraction. RESULTS: A cohort of 111 patients, mean age 79.3 (+/- 6.4), 68% women, received the sleep protocol. Patients required the protocol for a mean of 4.9 days per patient, totalling 539 patients-days. The overall adherence rate was 400/539 (74%) patient-days. The rate of complete nonadherence was 139/539 (26%), with reasons for nonadherence including nurse nonadherence in 30 (6%), patient refusal in 104 (19%), and medical contraindications in five (1%). The quality of sleep correlated strongly with the number of parts of the protocol received, suggesting a dose-response relationship, with the highest correlation for receiving two to three parts (p = .64, P < 0.001). The sleep protocol was successful in reducing SHD use from the baseline preintervention rate of 51/94 (54%) to 34/111 (31%) (P < .002). The sleep protocol had a stronger association with quality of sleep (p = .75, P = .001) than did SHDs (p = .07, P = .45). However, chronic SHD users were more likely to refuse the protocol than nonusers (64% vs 41%, P < .03) and received SHDs 4.5 times more often than nonusers (67% vs 15%, P = .001). CONCLUSION: The nonpharmacologic sleep protocol provides a feasible, effective, and nontoxic alternative to SHDs to promote sleep in older hospitalized patients. Use of the protocol can substantially decrease use of SHDs.     

Effects of mindset on the predictive validity of relationship constructs.

The authors investigated the effects of deliberative versus implemental mindsets on the predictive validity of relationship constructs. Dating students anticipating the transition from university to work deliberated about increasing their commitment or thought about how to maintain their relationships after graduation. As hypothesized, this mindset manipulation interacted with subsequent ratings of relationship closeness and perceived partner commitment to predict relationship status six months later. Ratings made by those in a deliberative mindset were more strongly associated with relationship survival than were similar ratings made by those in an implemental mindset. Deliberatives' relationship appraisals were only positive if their relationships were on a successful trajectory whereas implementals' relationship appraisals were positive whether their relationships were on course for success or dissolution. (PsycINFO Database Record (c) 2010 APA, all rights reserved)