We report observations of superradiance for atoms trapped in the near field of a photonic crystal waveguide (PCW). By fabricating the PCW with a band edge near the D(1) transition of atomic cesium, ...strong interaction is achieved between trapped atoms and guided-mode photons. Following short-pulse excitation, we record the decay of guided-mode emission and find a superradiant emission rate scaling as Γ̅(SR)∝N̅Γ(1D) for average atom number 0.19≲N̅≲2.6 atoms, where Γ(1D)/Γ'=1.0±0.1 is the peak single-atom radiative decay rate into the PCW guided mode, and Γ' is the radiative decay rate into all the other channels. These advances provide new tools for investigations of photon-mediated atom-atom interactions in the many-body regime.
The integration of nanophotonics and atomic physics has been a long-sought goal that would open new frontiers for optical physics, including novel quantum transport and many-body phenomena with ...photon-mediated atomic interactions. Reaching this goal requires surmounting diverse challenges in nanofabrication and atomic manipulation. Here we report the development of a novel integrated optical circuit with a photonic crystal capable of both localizing and interfacing atoms with guided photons. Optical bands of a photonic crystal waveguide are aligned with selected atomic transitions. From reflection spectra measured with average atom number N=1.1+/-0.4, we infer that atoms are localized within the waveguide by optical dipole forces. The fraction of single-atom radiative decay into the waveguide is Γ1D/Γ'≃(0.32±0.08), where Γ1D is the rate of emission into the guided mode and Γ' is the decay rate into all other channels. Γ1D/Γ' is unprecedented in all current atom-photon interfaces.
Experiments and numerical simulations are described that develop quantitative understanding of atomic motion near the surfaces of nanoscopic photonic crystal waveguides (PCWs). Ultracold atoms are ...delivered from a moving optical lattice into the PCW. Synchronous with the moving lattice, transmission spectra for a guided-mode probe field are recorded as functions of lattice transport time and frequency detuning of the probe beam. By way of measurements such as these, we have been able to validate quantitatively our numerical simulations, which are based upon detailed understanding of atomic trajectories that pass around and through nanoscopic regions of the PCW under the influence of optical and surface forces. The resolution for mapping atomic motion is roughly 50 nm in space and 100 ns in time. By introducing auxiliary guided-mode (GM) fields that provide spatially varying AC Stark shifts, we have, to some degree, begun to control atomic trajectories, such as to enhance the flux into the central vacuum gap of the PCW at predetermined times and with known AC Stark shifts. Applications of these capabilities include enabling high fractional filling of optical trap sites within PCWs, calibration of optical fields within PCWs, and utilization of the time-dependent, optically dense atomic medium for novel nonlinear optical experiments.
Aluminum alloys are in high demand for additive manufacturing (AM) processing. However, the physical properties of Al alloys are less favorable for the production of repeatable and reliable parts, ...with factors such as surface oxide scales, high thermal conductivity, and large solidification shrinkage. Despite these characteristics, processing strategies have been developed to overcome these hurdles. The objective of this article is to highlight the different microstructure–processing–properties characteristics for the three main families of aluminum alloys: pure, casting, and wrought chemistries. The article focuses on AM processes involving solidification, including powder bed and direct energy deposition for both powder and wire feedstock.
Aluminum consumption has been associated with various neurodegenerative diseases. Previous studies suggest that regular beer intake reverses the pro-oxidant and inflammatory statuses induced by ...aluminum nitrate intoxication. This paper aims to evaluate the in vitro antioxidant capacity and acetylcholinesterase inhibitory activity of non-alcoholic beer (NABeer), silicon or hops, as well as their effect on animal behavior (e.g. curiosity, immobilization, rearing, grooming, swimming) and brain antioxidant enzyme (activity and gene expression) and anti-inflammatory status in aluminum nitrate intoxicated rats. Male Wistar rats were divided into five groups: 1) Control, 2) Aluminum nitrate (450 μg/kg/day), 3) Aluminum nitrate plus NABeer, 4) Aluminum nitrate plus hops, and 5) Aluminum nitrate plus silicon. Hops showed the highest in vitro antioxidant capacity and silicon the highest anticholinesterase activity. In the Aluminum group the brain aluminum/silicon ratio increased with impairment of brain antioxidant and inflammatory statuses. NABeer, silicon and hops block the negative effect on the in vivo antioxidant and inflammatory statuses induced by Aluminum nitrate and improve swimming and rearing behavioral tests. The various positive results suggest that NABeer is useful as a functional multi-target drink in the prevention of some neurodegenerative events caused by aluminum intoxication. More studies are required to conclude present results.
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•Hops, Si and non-alcoholic beer show antioxidant and antiacetylcholinesterase activities.•Chronic Al(NO3)3 administration induces brain inflammation and oxidation in male rats.•Animal behavior impairment was observed in Al(NO3)3 intoxicated male rats.•Hops, Si and non-alcoholic beer arrest the negative effect of aluminum intoxication.
•We present a paper proposing a computational model based on artificial neural network to classify data patterns of elderly people in terms of dementia and Mild Cognitive Impairment.•We used ...real-world data from Brazilian hospital.•The proposal takes into account the gender, age, level of education, study time, and scores from cognitive tests (Mini-Mental State Examination, Semantic Verbal Fluency Test, Clinical Dementia Rating and Ascertaining Dementia).•This non-linear regression model is designed to classify healthy and pathological aging. The primary objective is to use this regression model to analyze the data set aiming to check which parameters are necessary to achieve high accuracy in the diagnosis of neurodegenerative disorders.
Background and Objectives: A huge number of solutions based on computational systems have been recently developed for the classification of cognitive abnormalities in older people, so that individuals at high risk of developing neurodegenerative diseases, such as Cognitive Impairment and Alzheimer?s disease, can be identified before the manifestation of the diseases. Several factors are related to these pathologies, making the diagnostic process a hard problem to solve. This paper proposes a computational model based on the artificial neural network to classify data patterns of older adults. Methods: The proposal takes into account the several parameters as diagnostic factors as gender, age, the level of education, study time, and scores from cognitive tests (Mini-Mental State Examination, Semantic Verbal Fluency Test, Clinical Dementia Rating and Ascertaining Dementia). This non-linear regression model is designed to classify healthy and pathological aging with machine learning techniques such as neural networks, random forest, SVM, and stochastic gradient boosting. We deployed a simple linear regression model for the sake of comparison. The primary objective is to use a regression model to analyze the data set aiming to check which parameters are necessary to achieve high accuracy in the diagnosis of neurodegenerative disorders. Results: The analysis demonstrated that the usage of cognitive tests produces median values for the accuracy greater than 90%. The ROC analysis shows that the best sensitivity performance is above 98% and specificity of 96% when the configurations have only cognitive tests. Conclusions: The presented approach is a valuable tool for identifying patients with dementia or MCI and for supporting the clinician in the diagnostic process, by providing an outstanding support decision tool in the diagnostics of neurodegenerative diseases.
The aim of this paper was to evaluate the oxidative stability of healthier lipid cooked meat systems (MS) in which pork backfat was replaced by a double emulsion (DE, W1/O/W2) prepared with ...hydroxytyrosol (HXT) within an inner aqueous phase and chia oil as lipid phase. Physical characteristics of DEs and oxidative stability of DEs and MS during chilled storage were analysed. In DEs, which were highly stable, the presence of HXT improved oxidative stability, increasing (P < 0.05) DPPH free radical scavenging and ferric reducing ability (FRAP) and reducing (P < 0.05) levels of thiobarbituric acid-reactive substances (TBARS). In MS, replacement of pork backfat by chia oil promoted lipid oxidation, which was more pronounced when chia oil was incorporated in the DE than when it was added in liquid form. HXT demonstrated antioxidative capacity, although it was less efficient when incorporated as part of a W1/O/W2 emulsion. In conclusion, MS including DE formulated with chia and HXT display oxidative stability throughout their commercial life, assuring successful development of potential healthier meat products.
•Double emulsions with chia oil and hydroxytirosol were used in healthy meat systems.•Hydroxytirosol showed antioxidant capacity in double emulsions and meat systems.•The antioxidant capacity of hydroxytirosol in meat systems varied with the way of incorporation.
Rotation with different active ingredients is among the most effective and recommended strategies to preserve the efficacy of anticoccidial drugs and reduce the emergence of resistance. Tools such as ...anticoccidial sensitivity tests (ASTs) are ideally used to make rational rotation programs and bring benefits to production. The objective of this study was to evaluate the sensitivity of E. acervulina (EA) and E. maxima (EM) from 3 different regions in Brazil, by using four ASTs. Feces samples weighing 6 to 7 kg were collected in the regions of São Paulo, Paraná, and Minas Gerais. Prevalent oocysts from feces were filtered, identified, and quantified to conduct 2 ASTs with EA and 2 with EM. The same experimental design was used in every AST (4 replicates per treatment, with 6 birds each, for a total of 240 birds). Treatment groups were a nonchallenged and nonmedicated control group (T1), a challenged and nonmedicated control group (T2), and the other groups challenged and treated with the following compounds: lasalocid (90 ppm – T3), maduramycin (6 ppm – T4), decoquinate (30 ppm – T5), nicarbazin+semduramicin (66 ppm – T6), monensin (110 ppm – T7), salinomycin (66 ppm – T8), narasin+nicarbazin (100 ppm – T9), and nicarbazin (125 ppm – T10). At the end of each AST (20 d), the percent change (delta value) between the treated group (T3 to T10) and the control group (T2) was calculated for the following variables: body weight gain, feed conversion ratio, lesion score, and an indicator of percentage of optimal anticoccidial activity (POAA) that included T2. Different sensitivity levels of EA and EM isolates could be identified. As a whole, drugs from T5 and T3 groups showed higher delta values when compared to other compounds, whereas the lowest sensitivity levels of these isolates were observed in groups T4 and T7. Despite some limiting factors, ASTs can be a good tool for strategic selection of anticoccidial drugs in order to maintain efficacy and extend the lifespan of these molecules.
A methodology using pulsed laser powder bed fusion to produce crack-free AM parts from Superalloy was demonstrated on Inconel 718. In the as-deposited condition, columnar grains with epitaxial growth ...were observed. The texture was observed to be towards (100) planes. Dendritic structure with average dendrite arm spacing of 0.37±0.12μm was observed, which suggested a cooling rate in the magnitude of 106K/s. The solidification front velocity ranging from 0.17 to 0.75m/s was calculated from KGT model. This high cooling rate and rapid solidification prevented the precipitation of both γ′ and γ″, and broke down the continuous feature of eutectic phases formed from the residual liquid phase during terminal solidification. The eutectics consisted of mainly discrete Laves phases and small portion of NbC. The discrete Laves phases contributed to the good solidification behavior of the Inconel 718 build. After solution annealing and two-step aging treatment, partial recrystallization occurred and resulted in the nucleation of small equiaxed grains. Laves phase dissolved and δ phase with needle-like shape formed. Precipitates also developed through the solid-state transformation during heat treatment.
•Pulsed laser powder bed fusion deposits were made using Inconel 718 powders.•Crack-free deposits were obtained due to the discrete feature of eutectics mainly consisting of Laves phase and small portion of NbC formed during terminal solidification.•Continuous growth model (CGM) was performed to validate the formation of Laves phase during rapid solidification.•After heat treatment, partial recrystallization was found to result in nucleation of small equiaxed grains. The texture of remaining columnar grains was still along (100) planes.•Small precipitates were formed through solid-state transformation during heat treatment, leading to higher hardness than the as-deposited condition.
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