496 research outputs found
Effect of bonding of a CO molecule on the conductance of atomic metal wires
We have measured the effect of bonding of a CO molecule on the conductance of
Au, Cu, Pt, and Ni atomic contacts at 4.2 K. When CO gas is admitted to the
metal nano contacts, a conductance feature appears in the conductance histogram
near 0.5 of the quantum unit of conductance, for all metals. For Au, the
intensity of this fractional conductance feature can be tuned with the bias
voltage, and it disappears at high bias voltage (above 200 mV). The
bonding of CO to Au appears to be weakest, and associated with monotomic Au
wire formation.Comment: 6 figure
Evidence for a single hydrogen molecule connected by an atomic chain
Stable, single-molecule conducting-bridge configurations are typically
identified from peak structures in a conductance histogram. In previous work on
Pt with H at cryogenic temperatures it has been shown that a peak near 1
identifies a single molecule Pt-H-Pt bridge. The histogram shows
an additional structure with lower conductance that has not been identified.
Here, we show that it is likely due to a hydrogen decorated Pt chain in contact
with the H molecular bridge.Comment: 4 pages, 4 figure
Highly conductive molecular junctions based on direct binding of benzene to platinum electrodes
Highly conductive molecular junctions were formed by direct binding of
benzene molecules between two Pt electrodes. Measurements of conductance,
isotopic shift in inelastic spectroscopy and shot noise compared with
calculations provide indications for a stable molecular junction where the
benzene molecule is preserved intact and bonded to the Pt leads via carbon
atoms. The junction has a conductance comparable to that for metallic atomic
junctions (around 0.1-1 Go), where the conductance and the number of
transmission channels are controlled by the molecule's orientation at different
inter-electrode distances.Comment: 4 pages, 4 figure
Morphological Characteristics of Breast and Thigh Muscles of Autochthonous Breeds of Chickens
Morphological characteristics of skeletal muscles of autochthonous breeds of chickens are very important for meat quality and comparison with current hybrids for intensive production. The autochthonous breeds used in the experiment were Sombor crested and Banat naked neck, both sexes. For the purposes of morphological examination, tissue samples were taken from the thigh muscle (m. biceps femoris) and muscles of the breast (m. pectoralis profundus) of 5 male and female animals of each breed. After a standard histological procedure for conventional light microscopy, samples were stained with hematoxylin - eosin. After the processing of the samples for the histochemical analysis, samples were stained with the enzyme succinate - dehydrogenase (SDH) with the aim of determining the presence of different muscle cell types (red, white and intermediate). Morphological parameters, in this study, were diameter of muscle cells, nucleocytoplasmic ratio of muscle cells, volume density of connective tissue within the muscle and the presence of red, white and intermediate muscle cell types. Comparison of diameters of muscle cells thigh and breast muscles between Sombor crested and Banat naked neck have showed that kind of muscle, race or gender have no significant effect on the differences in this parameter. There were no statistically significant differences in the nucleo-cytoplasmic ratio of the volume density of the connective tissue of muscles. Red muscle cells were, in both autochthonous breeds, significantly more represented in m. biceps femoris than m. pectoralis profundus. The results of this study indicate that no differences were observed between autochthonous breeds in morphological parameters for examined breast and thigh muscle
Newly Licensed RNs Describe What They Like Best about Being a Nurse
About 25% of newly licensed registered nurses (NLRNs) leave their first job within two years, but only 2% leave the nursing profession in this same timeframe. Therefore, the researchers sought to discover what new nurses like best about being a nurse, in hopes of gaining information that might help facilities to reduce turnover rates. Data were collected between January and March 2009 from 1,152 NLRNs licensed in 15 US states. Krippendorff's method was used to analyze survey responses. Five themes emerged: “providing holistic patient care,” “having an autonomous and collaborative practice,” “using diverse knowledge and skills to impact patient outcomes,” “receiving recognition,” and “having a job that is secure and stimulating.” Strategies are discussed that organizations might employ in helping NLRNs to realize what they best like about their work, which might lead to improved retention rates
Effects of Phytogenic Feed Additive and Enzyme on Growth Performance of Broilers Fed Diets with Reduced Energy Concentrations
The effects of dietary supplementation with phytogenic feed additives (PFA) and enzyme (E) on performance parameters were investigated using Ross 308 as hatched broilers fed standard diets or diets with reduced energy concentrations. Birds were assigned to 5 treatments with 5 replications each and fed either a standard basal diet or a re-formulated basal diet with reduced energy concentrations. Reduction was made according to enzyme matrix (Ronozyme WX, DSM). Treatments were: (1) Standard diet; (2) Negative control (NC) – 4% reduction in ME (3) NC + E; (4) NC + PFA (5) NC + E + PFA. Body weight and feed consumption were recorded weekly. Mortality was recorded on daily basis. Foot pad lesions were scored at day 35 using scale from 0 (no lesion) to 2 (lesion extending through skin). The results showed that birds fed Negative control diets had a significantly lower body weights (P0.05). Mortality and FCR did not differ significantly between treatments. Average foot pad lesion score was the highest in Negative control (1.05) and the lowest in NC+E (0.55).
In conclusion, re-formulation of diets for 4% energy reduction decreased broiler growth rate. Supplementation of diets with PFA improved live weight especially in combination with enzyme, hence confirming a growth-promoting effect of both phytogenics and enzymes in broilers
Effect of Litter Treatment on the Occurrence of Foot Pad Lesions
Pododermatitis (foot pad lesions) is one of the main welfare problems in modern broiler production in countries with developed poultry farming. Factors contributing to the occurrence of these lesions are nutrition, stocking density and material used for litter. There are a number of different procedures that can be applied in order to prevent and reduce the number of lesions with the most pronounced defects. The experiment was conducted on broiler chickens grown in 10 buildings of 240 m2 each. The stocking density was 35 kg/m2. The experiment was set up in five treatments with two replicates. Treatment one (T1) - control with a straw litter, treatment two (T2) - litter treated with microbial preparation Micropan®, treatment three (T3) – litter with addition of lignin, treatment four (T4) – litter with addition of lignin and Micropan® and treatment five (T5) - chopped straw without supplements. At the end of the experiment, on day 42 the intensity of the lesions was scored on the slaughter line. The presence of lesions was scored using scale from 0 (no lesions) to 3 (plantar pads with more than 50% damage). Based on the results of the trial it can be concluded that litter has a significant impact on the presence and the degree of foot pad lesions. The lowest score of foot pad lesions was observed in the treatment T5 (chopped straw). Different treatments of litters may also contribute to the solution of the problem of pododermatitis since the results in all treated groups (T2, T3, T4 and T5) were better when compared to the control
Stretching dependence of the vibration modes of a single-molecule Pt-H2-Pt bridge
A conducting bridge of a single hydrogen molecule between Pt electrodes is
formed in a break junction experiment. It has a conductance near the quantum
unit, G_0 = 2e^2/h, carried by a single channel. Using point contact
spectroscopy three vibration modes are observed and their variation upon
stretching and isotope substitution is obtained. The interpretation of the
experiment in terms of a Pt-H_2-Pt bridge is verified by Density Functional
Theory calculations for the stability, vibrational modes, and conductance of
the structure.Comment: 5 pages, 4 figure
A hybrid quantum-classical fusion neural network to improve protein-ligand binding affinity predictions for drug discovery
The field of drug discovery hinges on the accurate prediction of binding
affinity between prospective drug molecules and target proteins, especially
when such proteins directly influence disease progression. However, estimating
binding affinity demands significant financial and computational resources.
While state-of-the-art methodologies employ classical machine learning (ML)
techniques, emerging hybrid quantum machine learning (QML) models have shown
promise for enhanced performance, owing to their inherent parallelism and
capacity to manage exponential increases in data dimensionality. Despite these
advances, existing models encounter issues related to convergence stability and
prediction accuracy. This paper introduces a novel hybrid quantum-classical
deep learning model tailored for binding affinity prediction in drug discovery.
Specifically, the proposed model synergistically integrates 3D and spatial
graph convolutional neural networks within an optimized quantum architecture.
Simulation results demonstrate a 6% improvement in prediction accuracy relative
to existing classical models, as well as a significantly more stable
convergence performance compared to previous classical approaches.Comment: 5 pages, 3 figure
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