263 research outputs found

    Conductance of a single molecule anchored by an isocyanide substituent to gold electrodes

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    The effect of anchoring group on the electrical conductance of a single molecule bridging two Au electrodes was studied using di-substituted (isocyanide (CN-), thiol (S-) or cyanide (NC-)) benzene. The conductance of a single Au/1,4-diisocyanobenzene/Au junction anchored by isocyanide via a C atom (junction with the Au-CN bond) was 3×103G03 \times 10 ^{-3} G_{0} (2e2/h2e^{2}/h). The value was comparable to 4×103G04 \times 10 ^{-3} G_{0} of a single Au/1,4-benzenedithiol/Au junction with the Au-S bond. The Au/1,4-dicyanobenzene/Au molecular junction with the Au-NC bond did not show well-defined conductance values. The metal-molecule bond strength was estimated by the distance over which the molecular junction was stretched before breakdown. The stretched length of the molecular junction with the Au-CN bond was comparable to that of the Au junction, indicating that the Au-CN bond was stronger than the Au-Au bond.Comment: 3 figures, to be appear in Appl. Phys. Let

    Surface Acoustic Wave Single-Electron Interferometry

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    We propose an experiment to observe interference of a single electron as it is transported along two parallel quasi-one-dimensional channels trapped in a single minimum of a travelling periodic electric field. The experimental device is a modification of the surface acoustic wave (SAW) based quantum processor. Interference is achieved by creating a superposition of spatial wavefunctions between the two channels and inducing a relative phase shift via either a transverse electric field or a magnetic field. The interference can be used to estimate the decoherence time of an electron in this type of solid-state device

    Proximate composition, functional, and sensory properties of kadal (fermented grain flour) produced from whole and decorticated maize and pearl millet grains

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    Kadals are normally prepared from fermented cereal grains and the kadal flours are usually transformed into stiff dough called tuwo and consumed as staple food in many West African countries. Pearl millet (Mi) and maize (Mz) grains were decorticated and each of them was divided into four portions. The first portion was unfermented and the other portions were soaked in water separately for 48h (K2), for 72h (K3) and 96h (K4). Four portions each of whole maize and millet were subjected to the same soaking time, respectively. At the expiration of soaking time, each portion was washed, thoroughly rinsed, sun dried, milled and sieved to produce kadal flours. The unfermented whole and decorticated millet and maize flours served as the experimental controls. The functional properties and proximate compositions of twenty samples were evaluated using standard procedures and the organoleptic properties of the tuwo (kadal dough) prepared from them were evaluated without soup, and with okro soup. Results revealed significant variations (p<0.05) existed in the functional properties and proximate composition of kadal flours as well as the sensory attributes of the tuwo. Wettability of the kadal flours improved with soaking time, water absorption capacities decreased with fermentation time, as well as bulk densities though marginally. Dispersibility of the kadal flours were generally high (70.50-77%) and no significant difference was observed. Ash, protein and fat contents of the whole grain kadal flours were higher than that of decorticated, and there was slight decrease in these nutrients with soaking time. Again, moisture and carbohydrate were lower in whole grain kadal flours than in decorticated counterparts. On sensory attributes of the various tuwo produced, colour improved with soaking time more in the decorticated millet kadals. Decorticated millet had greater desirable flavor, which was not significantly different from that of whole millet kadals. Texture of 4th day kadal tuwo was better, with whole millet kadal tuwo rated better than that of the decorticated, unlike the texture of maize kadal tuwo. Control tuwo in general had poorer flavour, colour, texture and taste. The overall acceptability of the kadal tuwo was generally higher than the control. Millet kadal tuwo progressively improved with soaking time. The bottom line was that nutritional values were sacrificed to the improvement of sensory properties of the prepared kadal flours

    Comparative evaluation of the quality characteristics of composite flour bread produced from wheat-root tuber and wheat-grain legume flour blends

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    Adoption of composite flours for baked and non-baked goods has been trending and the underlying reasons include economic consideration, nutritional enhancement and amelioration of noncommunicable diseases through consumption of functional foods. Comparative study of the performance of popular food crop flours in bread making is not well documented although a lot work abound in the literature concerning specific blends from wheat and crop flours studied separately. But in the present study, comparative effects of 30% substitution of wheat flour with two common root tuber flours: sweet potato (Ps) and cassava (Ca) and three common grain legume flours in Nigeria: soybean (S), cowpea (Co), bambara groundnut (B) on bread quality were studied. Soybean, cowpea, and bambara groundnut were soaked and decorticated, toasted mildly and milled to obtain flours. Cassava and sweet potato roots were peeled, chopped, oven dried, milled and sieved. All purpose wheat flour was used to form blends with non-wheat flours on a constant ratio of 70:30 replacement weight basis, a total of five flour blends were obtained while 100% wheat flour served as the control. Bread were prepared using straight dough method of AACC. Thereafter, standard procedures were used to evaluate the proximate composition of the blends and bread, as well as the bread physical and sensory properties. Data generated were subjected to analysis of variance and mean values ±SE were reported. Consistently, soybean and bambara groundnut flours had significant higher content of protein, ash, crude fat and crude fibre than cassava and sweet potato flours which contained higher level of carbohydrates. The moisture contents of the flours were low and comparable. The moisture, crude protein, crude fat, total ash, crude fibre and carbohydrate contents of the flour blends and the refined wheat flour varied significantly (p<0.05) from 8.08-10.27%, 7.52-13.93%, 2.08-4.06%, 0.81-1.85%, 2.11-4.51% and 67.75-76.66% respectively. The same trend was repeated in the proximate composition of the composite flour breads although the calorific values decreased due to decrease in carbohydrate contents (58.00-47.64%), protein (6.37-11.98%), and increase in moisture (26.71-29.75%), relative to the values observed in the flour blends. Bread weights (196-223g) were comparable but the bread volumes (429-988ml) and specific loaf volumes (2.24-4.82ml/g) varied significantly (p<0.05) and wheat bread had the highest and legume flour treated breads had the least. Organoleptic properties of the wheat bread were rated better in some attributes however not significantly (p<0.05) different from those of 30% sweet potato and cassava breads. It was concluded that although nutritional value of legume containing breads were greater yet their bread volumes were depressed more, the higher protein of grain legume flours not withstanding confirming the fact that quality not quantity of the protein is the determinant factor in bread making potential of flours

    Workaholism, work engagement and child well-being: A test of the spillover-crossover model

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    This study examines how working parents’ work attitudes (i.e., workaholism and work engagement) are associated with their child’s psychological well-being. Based on the Spillover-Crossover model (SCM), we hypothesize that (a) work-to-family spillover (i.e., work-to-family conflict and facilitation) and (b) employee happiness will sequentially mediate the relationship between parents’ work attitudes and their child’s emotional and behavioral problems. A cross-sectional survey was conducted among Japanese dual-earner couples with pre-school child(ren). On the basis of valid data from 208 families, the hypothesized model was tested using structural equation modeling. For both fathers and mothers simultaneously, workaholism was positively related to work-to-family conflict, which, in turn, was negatively related to happiness. In contrast, work engagement was positively related to work-to-family facilitation, which, in turn, was positively related to happiness. Fathers’ and mothers’ happiness, in turn, were negatively related to their child’s emotional and behavioral problems. Results suggest that parents’ workaholism and work engagement are related to their child’s emotional and behavioral problems in opposite ways, whereby parents’ spillover and happiness mediate this relationship. These findin

    The novel heart-specific RING finger protein 207 is involved in energy metabolism in cardiomyocytes

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    A failing heart shows severe energy insufficiency, and it is presumed that this energy shortage plays a critical role in the development of cardiac dysfunction. However, little is known about the mechanisms that cause energy metabolic alterations in the failing heart. Here, we show that the novel RING-finger protein 207 (RNF207), which is specifically expressed in the heart, plays a role in cardiac energy metabolism. Depletion of RNF207 in neonatal rat cardiomyocytes (NRCs) leads to a reduced cellular concentration of adenosine triphosphate (ATP) and mitochondrial dysfunction. Consistent with this result, we observed here that the expression of RNF207 was significantly reduced in mice with common cardiac diseases including heart failure. Intriguingly, proteomic approaches revealed that RNF207 interacts with the voltage-dependent anion channel (VDAC), which is considered to be a key regulator of mitochondria function, as an RNF207-interacting protein. Our findings indicate that RNF207 is involved in ATP production by cardiomyocytes, suggesting that RNF207 plays an important role in the development of heart failure

    Arterial Remodeling and Endothelial Shear Stress Exhibit Significant Longitudinal Heterogeneity Along the Length of Coronary Plaques

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    Atherosclerosis is determined by both systemic risk factors and local vascular mechanisms. The arterial remodeling in response to plaque development plays a key role in atherosclerosis. Compensatory expansive remodeling is an adaptive mechanism that maintains lumen patency as a plaque develops. In contrast, excessive expansive remodeling, signifying an enlargement in vascular and lumen volume as a result of local plaque buildup, is a consistent attribute of high-risk plaques. Local hemodynamic factors, in particular low endothelial shear stress (ESS), is an intensely proinflammatory and proatherogenic stimulus and largely accounts for the spatially diverse distribution of atherosclerotic plaques. However, plaque, remodeling and ESS have hitherto been investigated only in the cross-sectional arterial axis and their distribution in the longitudinal axis of individual plaques has not been characterized

    Complement in patients receiving maintenance hemodialysis: functional screening and quantitative analysis

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    <p>Abstract</p> <p>Background</p> <p>The complement system is vital for innate immunity and is implicated in the pathogenesis of inflammatory diseases and the mechanism of host defense. Complement deficiencies occasionally cause life-threatening diseases. In hemodialysis (HD) patients, profiles on complement functional activity and deficiency are still obscure. The objectives of the present study were to measure the functional complement activities of the classical pathway (CP), lectin pathway (LP) and alternative pathway (AP) using a novel method and consequently to elucidate the rates of deficiencies among HD patients.</p> <p>Methods</p> <p>In the present study, 244 HD patients at one dialysis center and 204 healthy controls were enrolled. Functional complement activities were measured simultaneously using the Wielisa<sup>®</sup>-kit. The combination of the results of these three pathway activities allows us to speculate which candidate complement is deficient; subsequently, the deficient complement was determined.</p> <p>Results</p> <p>All three functional complement activities were significantly higher in the HD patients than in the control group (P < 0.01 for all cases). After identifying candidates in both groups with complement deficiencies using the Wielisa<sup>®</sup>-kit, 16 sera (8.8%) with mannose-binding lectin (MBL) deficiency, 1 serum (0.4%) with C4 deficiency, 1 serum (0.4%) with C9 deficiency, and 1 serum (0.4%) with B deficiency were observed in the HD group, and 18 sera (8.8%) with MBL deficiency and 1 serum (0.5%) with B deficiency were observed in the control group. There were no significant differences in the 5-year mortality rate between each complement-deficient group and the complement-sufficient group among the HD patients.</p> <p>Conclusion</p> <p>This is the first report that profiles complement deficiencies by simultaneous measurement of functional activities of the three complement pathways in HD patients. Hemodialysis patients frequently suffer from infections or malignancies, but functional complement deficiencies do not confer additional risk of mortality.</p

    Possible Existence of Lysosome-Like Organella within Mitochondria and Its Role in Mitochondrial Quality Control

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    The accumulation of unhealthy mitochondria results in mitochondrial dysfunction, which has been implicated in aging, cancer, and a variety of degenerative diseases. However, the mechanism by which mitochondrial quality is regulated remains unclear. Here, we show that Mieap, a novel p53-inducible protein, induces intramitochondrial lysosome-like organella that plays a critical role in mitochondrial quality control. Mieap expression is directly regulated by p53 and is frequently lost in human cancer as result of DNA methylation. Mieap dramatically induces the accumulation of lysosomal proteins within mitochondria and mitochondrial acidic condition without destroying the mitochondrial structure (designated MALM, for Mieap-induced accumulation of lysosome-like organelles within mitochondria) in response to mitochondrial damage. MALM was not related to canonical autophagy. MALM is involved in the degradation of oxidized mitochondrial proteins, leading to increased ATP synthesis and decreased reactive oxygen species generation. These results suggest that Mieap induces intramitochondrial lysosome-like organella that plays a critical role in mitochondrial quality control by eliminating oxidized mitochondrial proteins. Cancer cells might accumulate unhealthy mitochondria due to p53 mutations and/or Mieap methylation, representing a potential cause of the Warburg effect
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