Influence of fibre and matrix failure strain on static and fatigue properties of carbon fibre-reinforced plastics

The potential benefits of the overall strength of carbon fibre-reinforced plastics with conventional matrix systems can only be realized to a relatively small extent in view of the fact that design criteria for CFRP components presently allow, for aerospace use, a maximum strain of about 0·4%. Under static loading conditions first matrix cracks must be expected in the transverse plies above 0·4% strain. Shifting the maximum allowable strain level to higher values would significantly increase the profitability of composites. It will be shown in the present paper that increasing the matrix failure strain (ductility) will yield a pronounced improvement of the mechanical properties (under static and fatigue loading) and a shift of the crack initiation level to higher strain values.

Further improvements of carbon fibres, to the extent of developing fracture strains of about 1·8%, require adapted matrix systems. In composites made from high-strain fibres together with a ductile matrix system further pronounced improvements in mechanical properties can be achieved.     

Fatty acids in the lipids of Drosophila heads: effects of visual mutants, carotenoid deprivation and dietary fatty acids

Lipids of Drosophila heads were extracted and separated by high-performance thin-layer chromatography. Fatty acid compositions of major phospholipids as well as of triglycerides were analyzed by gas-liquid chromatography. Proportions of the major fatty acids (14:0, 16:0, 16:1, 18:0, 18:1, 18:2, 18:3) varied depending on the lipid analyzed. Docosahexaenoic acid (22:6), common in vertebrate photoreceptors and brain, and arachidonic acid (20:4), a precursor of eicosanoids, were lacking. A comparison of the fatty acid composition of the diet vs. the head suggested that Drosophila can desaturate but may not be able to elongate fatty acid carbon chains. Fatty acid analyses were carried out after the following visual system alterations: i) the transduction mutant where no receptor potential results from a deficit in phospholipase C; ii) an allele of eyes absent; iii) the mutant outer rhabdomeres absent which lacks visual pigment and rhabdomeres in the predominant type of compound eye receptor, rhabdomeres 1 through 6; and iv) carotenoid deprivation which reduces opsin and rhabdomere size. We also evaluated aging by comparing newly-emerged vs. aged wild-type flies. Alterations in fatty acid composition based on some of these manipulations were found. Based on comparisons between flies reared on media differing in C16 and C18, there is an indication that diet readily affects tissue fatty acid composition.     

The effect of normative beliefs on anticipated emotions.

In 3 experiments, Ss were asked how they would or should make hypothetical decisions and how they would react emotionally to the options or outcomes. The choices were those in which departures from proposed normative models had previously been found: omission bias, status quo bias, and the person–causation effect. These effects were found in all judgments, including judgments of anticipated emotion. Arguments against the departures affected judgments of anticipated emotion as well as decisions, even though the arguments were entirely directed at the question of what should be done. In all but one study, effects of these arguments on anticipated emotion were as strong as their effects on decisions or normative beliefs. Thus, in many situations, people think that their emotional reactions will fall into line with their normative beliefs. In other situations, some people think that their emotional reactions have a life of their own. It is suggested that both normative beliefs and anticipated emotions affect decisions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Social Corroboration and Opinion Extremity

Four studies found that social corroboration of one's (pro/con) attitudinal position leads to increases in attitude extremity. Study 1 focused on attraction ratings made by college women. This study demonstrated both increases in opinion extremity following corroboration and decreases in opinion extremity following contradiction. Study 2 focused on dental chair comfort ratings made by dental patients and found greater opinion extremity following corroboration from either fellow patients or the dentist. Study 3 reported greater charity donation amounts as well as heightened opinion confidence following corroboration. Study 4 replicated Study 1 varying duration of stimulus exposure and found that, as predicted, confidence scores were affected more by the corroboration/contradiction manipulation when initial exposures were brief. Unexpectedly, however, the affect of corroboration on attraction ratings, was not moderated by initial exposure time. Rather, across both long and short exposure times, attraction scores were most extreme following corroboration and least extreme following contradiction. Path analyses in Study 4 supported the view that this association between corroboration and extremity was mediated by confidence. This research indicates that the relationship between corroboration and opinion extremity appears to be respectably robust across populations and target variables, and is not specific to sensitive within subject designs. Moreover, Study 3 indicates that social corroboration is capable of increasing the extremity of behavior having real consequences for participants. The data are discussed in terms of possible moderator variables, as well as theories of group polarization and opinion extremity.     

Clinical case of the month. The association of Hodgkin's disease and nephrotic syndrome

The nephrotic syndrome is a rare complication of Hodgkin's disease. The majority of the cases do not respond to corticosteroids but are cured by the treatment of the lymphoma. We describe a patient with a nephrotic syndrome at the time of diagnosis of mixed cellularity Hodgkin's disease and the resolution of this nephrotic syndrome by MOPP-ABV chemotherapy.     

Association between depressive symptoms and mortality in older women. Study of Osteoporotic Fractures Research Group

BACKGROUND: Major depression is associated with increased mortality, but it is not known whether patients who report depressive symptoms have greater mortality. SUBJECTS AND METHODS: We performed a prospective cohort study of 7518 white women 67 years of age or older who were recruited from population-based listings in Baltimore, Md, Minneapolis, Minn, Portland, Ore, and the Monongahela Valley, Pa. Participants completed the Geriatric Depression Scale (short form) and were considered depressed if they reported 6 or more of 15 possible symptoms of depression. Women were followed up for an average of 6 years. If a participant died, we obtained a copy of the official death certificate and hospital records, if available, and used International Classification of Diseases, Ninth Revision, codes to classify death attributable to cardiovascular, cancer, or noncancer, noncardiovascular cause. RESULTS: Mortality during 7-year follow-up varied from 7% in women with no depressive symptoms to 17% in those with 3 to 5 symptoms to 24% in those with 6 or more symptoms of depression (P<.001). Of 473 women (6.3%) with 6 or more depressive symptoms at baseline, 24% died (111 deaths in 2610 woman-years of follow-up) compared with 11% of women who reported 5 or fewer symptoms of depression (760 deaths in 41 460 woman-years of follow-up) (P<.001). Women with 6 or more depressive symptoms had a 2-fold increased risk of death (age-adjusted hazard ratio [HR], 2.14; 95% confidence interval [CI], 1.75-2.61; P<.001) compared with those who had 5 or fewer depressive symptoms. This association remained strong after adjusting for potential confounding variables, including history of myocardial infarction, stroke, diabetes mellitus, hypertension, chronic obstructive pulmonary disease, smoking, perceived health, and cognitive function (HR, 1.47; 95% CI, 1.14-1.88; P=.003). Depressive symptoms were associated with an increased adjusted risk of death from cardiovascular diseases (HR, 1.8; 95% CI, 1.2-2.5; P= .003), and non-cancer, noncardiovascular diseases (HR, 1.8; 95% CI, 1.2-2.7; P = .01), but were not associated with deaths from cancer (HR, 1.0; 95% CI, 0.6-1.7; P=.93). CONCLUSIONS: Depressive symptoms are a significant risk factor for cardiovascular and noncancer, noncardiovascular mortality but not cancer mortality in older women. Whether depressive symptoms are a marker for, or a cause of, life-threatening conditions remains to be determined.     

Identification of a novel inhibitor of mitogen-activated protein kinase kinase

The compound U0126 (1,4-diamino-2,3-dicyano-1, 4-bis[2-aminophenylthio]butadiene) was identified as an inhibitor of AP-1 transactivation in a cell-based reporter assay. U0126 was also shown to inhibit endogenous promoters containing AP-1 response elements but did not affect genes lacking an AP-1 response element in their promoters. These effects of U0126 result from direct inhibition of the mitogen-activated protein kinase kinase family members, MEK-1 and MEK-2. Inhibition is selective for MEK-1 and -2, as U0126 shows little, if any, effect on the kinase activities of protein kinase C, Abl, Raf, MEKK, ERK, JNK, MKK-3, MKK-4/SEK, MKK-6, Cdk2, or Cdk4. Comparative kinetic analysis of U0126 and the MEK inhibitor PD098059 (Dudley, D. T., Pang, L., Decker, S. J., Bridges, A. J., and Saltiel, A. R. (1995) Proc. Natl. Acad. Sci U. S. A. 92, 7686-7689) demonstrates that U0126 and PD098059 are noncompetitive inhibitors with respect to both MEK substrates, ATP and ERK. We further demonstrate that the two compounds bind to deltaN3-S218E/S222D MEK in a mutually exclusive fashion, suggesting that they may share a common or overlapping binding site(s). Quantitative evaluation of the steady state kinetics of MEK inhibition by these compounds reveals that U0126 has approximately 100-fold higher affinity for deltaN3-S218E/S222D MEK than does PD098059. We further tested the effects of these compounds on the activity of wild type MEK isolated after activation from stimulated cells. Surprisingly, we observe a significant diminution in affinity of both compounds for wild type MEK as compared with the deltaN3-S218E/S222D mutant enzyme. These results suggest that the affinity of both compounds is mediated by subtle conformational differences between the two activated MEK forms. The MEK affinity of U0126, its selectivity for MEK over other kinases, and its cellular efficacy suggest that this compound will serve as a powerful tool for in vitro and cellular investigations of mitogen-activated protein kinase-mediated signal transduction.     

Thermal latency in radiofrequency ablation

The relative nail producing capacity of different regions within the nail matrix has not been quantified. In order to do this, the number of nail plate cells in the dorsoventral axis of 12 human great toenails was counted at five sites in the longitudinal axis, and compared with direct measurements of nail plate thickness at the same sites. The mean number of nail cells in the nail plate reached a maximum at the lunula, with no further increase along the length of the nail bed. At the mid-point between the proximal tip of the germinal matrix and lunula, mean cell numbers achieved 81% of the value at the lunula. Mean nail thickness was only 90% of its maximum at the lunula, with a further significant increase (P = 0.02) between the lunula and end of the nail bed. These observations suggest that the proximal nail matrix is the main source of nail within the matrix. This is consistent with clinical experience where distal matrix surgery has a low potential for scarring in comparison with proximal matrix surgery. The additional finding of increased nail thickness, but not cell numbers, along the nail bed make it likely that cells within the nail plate change shape as they move distally.