We report an experiment to test quantum interference, entanglement, and nonlocality using two dissimilar photon sources, the Sun and a semiconductor quantum dot on the Earth, which are separated by ...∼150 million kilometers. By making the otherwise vastly distinct photons indistinguishable in all degrees of freedom, we observe time-resolved two-photon quantum interference with a raw visibility of 0.796(17), well above the 0.5 classical limit, providing unambiguous evidence of the quantum nature of thermal light. Further, using the photons with no common history, we demonstrate postselected two-photon entanglement with a state fidelity of 0.826(24) and a violation of Bell inequality by 2.20(6). The experiment can be further extended to a larger scale using photons from distant stars and open a new route to quantum optics experiments at an astronomical scale.
Feelings of inferiority are complex emotions that usually indicate perceived weakness and helplessness. A lack of timely and effective interventions may bring serious consequences to individuals with ...inferiority feelings. Due to privacy concerns, those people often hesitate to seek face-to-face help, but they usually spontaneously share their feelings on social media, which makes social media a good resource for ample inferiority-related data. We randomly selected a sample of posts indicating inferiority feelings to explore the causes of inferiority. Through language analysis and natural language processing, we constructed a Word2Vec model of inferiority based on social media data and applied it to the cause analysis of inferiority feelings. The main causes of inferiority feelings are personal experience, social interaction, love relationship, etc. People feeling inferior about their personal experiences usually are largely influenced by their ways of thinking and life attitudes. Social and emotional factors overlap somewhat in the development of inferiority. In love relationships, males are more prone to inferiority feeling than females. These findings will help relevant institutions and organizations better understand people with inferiority feelings and facilitate the development of targeted treatment for those with potential self-esteem problems.
This report outlines a highly sensitive and facile electrochemiluminescence (ECL) sensing platform based on a novel high-quantum-yield Au-nanocluster (AuNC) probe for glutathione (GSH) detection. ...Owing to the prominent quenching effect of GSH on the ECL of the AuNCs, the proposed ECL nanosensor showed a wide response to GSH in the ranges of 1.0 × 10-9–1.0 × 10-5M and 1.0 × 10-5–1.0 × 10-1M and a low detection limit of 3.2 × 10-10M. In addition, the proposed system exhibited good selectivity for GSH in the presence of other chemical/biological interferences. Moreover, since no further functionalization of AuNC-based sensor interface was necessary, together with the stability, high sensitivity and selectivity of the proposed nanosensor, this convenient approach was able to successfully detect GSH in both of human urine samples and blood samples with excellent recoveries, which indicated its promising application under physiological conditions. Of significant importance is that this study not only helps in gaining a better understanding of the applicability of the ECL properties of AuNCs, but also provides a new avenue for the design and development of ECL sensors based on the novel high-quantum-yield AuNC-based probe and other functional-metal-based NC probes.
•Facile ECL sensing platform based on high-quantum-yield AuNC probe.•A high performance ECL method for glutathione determination.•Detection of glutathione in human urine samples.•This sensing platform can be adapted to measure other physiologically important compounds.•A new avenue for design and development of other functional-metal NC probe-based ECL sensors.
•This study documents the presence of a Paleoproterozoic (ca. 2.15Ga) ophiolitic mélange in the northern Huangling Dome of the Yangtze craton.•The mélange consists of Paleoproterozoic ...mafic–ultramafic blocks dispersed in a sedimentary matrix.•The ophiolitic fragments have been overprinted by subduction metasomatism at 2.05–2.03Ga and high-pressure granulite facies metamorphism at 2.0–1.95Ga.
We document for the first time the presence of a Paleoproterozoic ophiolitic mélange in the Archean–Paleoproterozoic Kongling Complex in the northern Huangling Dome, Yangtze craton, South China. Detailed field mapping, petrographic, geochronological and geochemical studies reveal that the mélange consists of a suite of amphibolite facies mafic and ultramafic tectonic blocks including serpentinized harzburgite, olivine pyroxenite, pyroxenite, diabase, gabbro and basalt dispersed in a strongly sheared metasedimentary matrix. The mélange displays polyphase deformation and northwest-verging nappe structures, and underwent amphibolite to granulite facies metamorphism in the Paleoproterozoic (2.0–1.95Ga). The metasedimentary rocks are composed mainly of garnet-biotite-plagioclase gneiss, mica schist, mica-graphite schist, marble, quartzite, and banded iron formation (BIF). The mafic–ultramafic rock association shares the lithological and geochemical characteristics of Phanerozoic suprasubduction zone ophiolites.
LA-ICP-MS U–Pb dating of zircons from the diabase yield ages between 2142 and 2148Ma for the magmatic cores and between 2042–2048Ma for the metamorphic rims. Zircon cores have εHf (t) values ranging from +5.4 to +10.3 (average=+7.2) with corresponding TDM1 ages of 2.24Ga, indicating that these rocks are remnants of juvenile crust derived from the depleted mantle at ca. 2.2Ga. All rock types in the mélange underwent Paleoproterozoic (2.0–1.95Ga) amphibolite–granulite facies metamorphism and were intruded by syn-metamorphic granite (∼2.0Ga), post-collisional (ca.1.85Ga) granite and mafic dykes. Intrusion age of one quartz monzonitic dyke crosscutting the serpentinized harzburgite is 1999Ma, constraining the minimum emplacement age of the mafic–ultramafic complex. The mafic–ultramafic rocks within the metasedimentary matrix in the northern Huangling Dome are fragments of a ca. 2.15Ga suprasubduction zone ophiolite that was incorporated into the suture zone during the accretionary-collisional process. The mélange recognized in the northern Yangtze craton provides important evidence for the Paleoproterozoic subduction and accretion processes possibly associated with the amalgamation of the proposed Columbia supercontinent.
An extruded profile of Al-Mg-Si alloy was metal-inert-gas-welded (MIG-welded) with an ER5356 filler wire and the microstructures, mechanical properties and fatigue behavior of the joints were ...investigated. Compared with the base material (BM), coarser grains are present in the heat-affected zone (HAZ) as a result of abnormal growth in the welding process. The average grain sizes of the weld zone (WZ) and BM were 40.8 µm and 16.8 µm, respectively. The ultimate tensile strength (UTS) of the MIG-welded joint and BM were 210.3 MPa and 274.8 MPa, respectively, thus, the weld joint efficiency was approximately 76.5%. Fracture appeared at the location with the minimum hardness in the HAZ of the MIG-welded joint during tensile tests. Based on the fatigue testing experiment with 107 cycles, the conditional fatigue strengths of the MIG-welded joint and BM were 61.7 MPa and 141.3 MPa, respectively. Welding defects, such as coarse secondary phase, welding pores and incomplete fusion, caused local stress concentration which initiated fatigue crack and apparently increased the fatigue crack growth rate of the MIG-welded joint, ultimately causing the premature fracture of the joint at the WZ.
Three-dimensional (3D) geological models are typical data sources in 3D mineral prospectivity modeling. However, identifying prospectivity-informative predictor variables from 3D geological models is ...a challenging and work-intensive task. Motivated by the ability of convolutional neural networks (CNNs) to learn intrinsic features, in this paper, we present a novel method that leverages CNNs to learn 3D mineral prospectivity from 3D geological models. By exploiting this learning ability, the proposed method simplifies the complex correlations of mineralization and circumvent the need for designing the predictor variables. Specifically, to analyze unstructured 3D geological models using CNNs—whose inputs should be structured—we develop a 2D CNN framework where the geometry of geological boundary is compiled and reorganized into multi-channel images and fed into the CNN. This ensures the effective and efficient training of the CNN while facilitating the representation of mineralization control. The presented method is applied to a typical structure-controlled hydrothermal deposit, the Dayingezhuang gold deposit in eastern China; the presented method is compared with prospectivity modeling methods using designed predictor variables. The results show that the presented method has a performance boost in terms of the 3D prospectivity modeling and decreases the workload and prospecting risk in the prediction of deep-seated orebodies.
•A 3D mineral prospectivity modeling method based on convolutional neural networks.•Deep learning of 3D mineral prospectivity from the 3D geological models.•Reorganizing the unstructured 3D geological models into convolutional neural networks.•A 3D prospectivity modeling framework free of hand-designed predictor variables.
Heavy metal ions (HMIs), including Cu
, Ag
, Cd
, Hg
, and Pb
from the environment pose a threat to human beings and can cause a series of life-threatening diseases. Therefore, colorimetric sensors ...with convenience and flexibility for HMI discrimination are still required. To provide a solution, a peroxidase-like activity-based colorimetric sensor array of citrate-capped noble metal nanozymes (osmium, platinum, and gold) has been fabricated. Some studies reported that some HMIs could interact with the noble metal nanozymes leading to a change in their peroxidase-like activity. This phenomenon was confirmed in our work. Based on this principle, different concentrations of HMIs (Cu
, Ag
, Cd
, Hg
, and Pb
) were discriminated. Moreover, their practical application has been tested by discriminating HMIs in tap water and SiYu lake water. What is more, as an example of the validity of our method to quantify HMIs at nanomolar concentrations, the LOD of Hg
was presented. To sum up, our study not only demonstrates the differentiation ability of this nanozyme sensor array but also gives hints for using nanozyme sensor arrays for further applications.
Capping molecules on the surface of nanomaterials not only enhance the dispersion and stability of nanomaterials but also greatly facilitate their surface modification and biological applications. ...However, most capping molecules can severely block the active sites of the catalytic core, thereby decreasing the enzymatic activity of nanomaterial-based enzyme mimics. This work demonstrates the superiority of chitosan (Ch) as a capping molecule for synthesizing catalytic platinum nanoparticles (PtNPs). The experimental results show that Ch simultaneously exhibits an excellent stabilizing effect and enhances the oxidase-like activity of PtNPs. Kinetic studies indicate that Ch-PtNPs have a higher affinity for 3,3',5,5'-tetramethylbenzidine (TMB) than other kinds of oxidase mimics. Furthermore, the TMB chromogenic reaction catalyzed by Ch-PtNPs is found to be much faster in an acidic medium, thus adapting well to the optimal pH for acid phosphatase (ACP). Therefore, a novel colorimetric approach for ACP determination is developed for the first time, which is based on the Ch-PtNP-catalyzed oxidation of TMB, the inhibitory effect of ascorbic acid (AA) on the oxidase-like activity of Ch-PtNPs, and the ACP-catalyzed hydrolysis of AA 2-phosphate (AAP) into AA. The linear range for ACP is 0.25-2.5 U L
and the limit of detection is measured to be 0.016 U L
. This new colorimetric method is utilized to detect ACP in real biological samples and to screen ACP inhibitors. We believe that these new PtNPs, which exhibit high colloidal stability, excellent catalytic performance, good biocompatibility, simple preparation, and easy modification, can be promising candidates for a broad range of applications in optical sensing, environmental monitoring, clinical diagnosis, and drug discovery.
Ischemic stroke often induces excessive neuronal autophagy, resulting in brain damage; meanwhile, inflammatory responses stimulated by ischemia exacerbate neural injury. However, interactions between ...neuronal autophagy and microglial inflammation following ischemic stroke are poorly understood. CX3CL1/fractalkine, a membrane-bound chemokine expressed on neurons, can suppress microglial inflammation by binding to its receptor CX3CR1 on microglia. In the present study, to investigate whether autophagy could alter CX3CL1 expression on neurons and consequently change microglial inflammatory activity, middle cerebral artery occlusion (MCAO) was established in Sprague-Dawley rats to model ischemic stroke, and tissues from the ischemic penumbra were obtained to evaluate autophagy level and microglial inflammatory activity. MCAO rats were administered 3-methyladenine (autophagy inhibitor) or Tat-Beclin 1 (autophagy inducer). Western blot assays were conducted to quantify expression of Beclin-1, nuclear factor kappa B p65 (NF-κB), light chain 3B (LC3B), and CX3CL1 in ischemic penumbra. Moreover, immunofluorescence staining was performed to quantify numbers of LC3B-, CX3CL1-, and Iba-1-positive cells in ischemic penumbra. In addition, enzyme linked immunosorbent assays were utilized to analyze concentrations of tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), interleukin 1 beta (IL-1β), and prostaglandin E2 (PGE2). A dry/wet weight method was used to detect brain water content, while 2,3,5,-triphenyltetrazolium chloride staining was utilized to measure infarct volume. The results demonstrated that autophagy signaling (Beclin-1 and LC3B expression) in penumbra was prominently activated by MCAO, while CX3CL1 expression on autophagic neurons was significantly reduced and microglial inflammation was markedly activated. However, after inhibition of autophagy signaling with 3-methyladenine, CX3CL1 expression on neurons was obviously increased, whereas Iba-1 and NF-κB expression was downregulated; TNF-α, IL-6, IL-1β, and PGE2 levels were decreased; and cerebral edema was obviously mitigated. In contrast, after treatment with the autophagy inducer Tat-Beclin 1, CX3CL1 expression on neurons was further reduced; Iba-1 and NF-κB expression was increased; TNF-α, IL-6, IL-1β, and PGE2 levels were enhanced; and cerebral edema was aggravated. Our study suggests that ischemia-induced neuronal autophagy facilitates microglial inflammatory injury after ischemic stroke, and the efficacy of this process may be associated with downregulated CX3CL1 expression on autophagic neurons.
There is a continuing high demand to design effective sensors for the determination of heavy metal ions (HMIs) since they are hazardous to both human health and the environment. In this study, we ...reported a facile fluorescent sensor array for rapid discrimination of HMIs based on a single gold nanocluster (AuNC) probe. This AuNC probe was prepared by using 2-mercapto-1-methylimidazole (MMI) as a ligand and polyvinypyrrolidone (PVP) as a dispersing agent. The fluorescence emission of PVP/MMI-AuNC was observed to be closely related to the pH value of the aqueous solution, which displays yellow (λmax = 512 nm) and red (λmax = 700 nm) fluorescence at pH 12.0 and 6.0, respectively. Further experiments indicated that different HMIs can produce differential effects on the photoluminescence of PVP/MMI-AuNC and thus generate distinct fluorescent responses at 512 and 700 nm. On the basis of this phenomenon, a fluorescent sensor array based on the PVP/MMI-AuNC was then built by simply changing pH value in the sensor element. A total of seven HMIs had their unique response patterns and were successfully distinguished by hierarchical cluster analysis and linear discriminant analysis both in buffer solution and spiked water samples, achieving 100% identification accuracy. This study provides a simple and powerful fingerprinting sensing platform for multiple HMIs, showing broad application prospects in the field of environmental monitoring.
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•A single-probe-based sensor array for HMI discrimination is achieved.•PVP/MMI-AuNC with tunable emission is synthesized and used as the sole probe.•This AuNC produces differential fluorescent signals at 512 and 700 nm against HMIs.•A total of seven HMIs are well discriminated with 100% classification accuracy.•The proposed method offers a new way to fabricate low-number element-based sensing array.
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