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Abstract The global monopole solutions which give rise to quite unusual physical phenomena have captured considerable attention. In this paper, we study the Einstein ring of the spherically symmetric AdS black hole solution with a global monopole based on the AdS/CFT correspondence. With the help of the given response function of the QFT on the boundary, we construct the holographic images of the black hole in the bulk. Our results exhibit the absolute amplitude of total response function $$|\langle \mathcal {O}\rangle |$$ | ⟨ O ⟩ | increases with the decrease of the monopole parameter b and the temperature T. And the frequency $$\omega $$ ω of the Gaussian source will also increase the absolute amplitude. These parameters also affects the Einstein ring. With the change of the observation position, this ring will change from the concentric stripe to a luminosity-deformed ring, or light points. And the monopole parameter has an effect on the brightness and the position of Einstein ring. All these results imply that the holographic images can be used as an effective tool to distinguish different types of black holes for fixed wave source and optical system. These theoretical proposal opens a door to gravitational phenomena on strongly correlated material. Therefore, the holographic Einstein ring is of great theoretical and experimental significance for our research. In theory, it provides us a new way to find a necessary condition for the existence of the dual black hole. And experimentally speaking, if we can realize suitable targets for observing AdS black holes successfully, we would be able to observe Einstein rings by tabletop experiments when we apply localized sources on such materials and measure their responses.

Abstract With the help of AdS/CFT correspondence, we derive the desired response function of QFT on the boundary of the non-commutative black hole. Using the virtual optical system with a convex lens, we obtain the Einstein rings of the black hole from the response function. All the results show that the holographic ring always appears with the concentric stripe when the observer located at the north pole. With the change of the observation position, the ring changes into a luminosity-deformed ring, or bright spot. We also investigate the effect of the non-commutative parameter on the ring and find the ring radius becomes larger as the parameter increases. The effect of the temperature on the ring radius is also investigated, it is found that the higher the temperature, the smaller the ring radius. In addition, we also obtain the ingoing angle of the photon via geometric optics, as expected, this angle is consistent well with the angle of the Einstein ring obtained via holography.

Under the help of AdS/CFT correspondence, the Einstein ring of a charged black hole in conformal gravity has been studied. As an alternative to standard Einstein’s theory, the conformal gravity is both renormalizable and unitary. And such conformal theory can naturally solve some troublesome problems in physics, such as the quantum gravity problem, the dark matter problem and so on. Considering the conformal gravity has many advantages, therefore in this paper, we study Einstein ring and the effect of gravity-related parameters c0, temperature T and chemical potential u on such Einstein ring in the conformal gravity through the holographic method. Explicitly, imposing an oscillating Gauss source on one side of the AdS boundary which propagates in the bulk, the response functions are derived on the other side of the boundary. Given the proposed wave optics system, the Einstein rings are observed as expected. All these results reveal that when the observer locates at the north pole, there always exists the Einstein ring and surrounding concentric stripes. And such ring becomes into a luminosity-deformed ring or light spot while the observer departs away from the north pole. We also investigate the effect of temperature T, chemical potential u and gravity-related parameters c0 on the ring radius. We find the ring radius increases with the decrease of the temperature, increase of the chemical potential, and increase of the gravity-related parameters respectively. And more, in conformal gravity, because the charge does not appear in the metric but is given by the constraint relation, the chemical potential affects the radius of the ring differently compared with that in Einstein’s gravity. To check the results in the framework of holography, we investigate the ingoing angle of photon at the photon ring via geometric optics and find it is consistent with the angle of Einstein ring obtained via holography.

Background: Semantic segmentation is crucial in medical image diagnosis. Traditional deep convolutional neural networks excel in image classification and object detection but fall short in segmentation tasks. Enhancing the accuracy and efficiency of detecting high-level cervical lesions and invasive cancer poses a primary challenge in segmentation model development. Methods: Between 2018 and 2022, we retrospectively studied a total of 777 patients, comprising 339 patients with high-level cervical lesions and 313 patients with microinvasive or invasive cervical cancer. Overall, 1554 colposcopic images were put into the DeepLabv3+ model for learning. Accuracy, Precision, Specificity, and mIoU were employed to evaluate the performance of the model in the prediction of cervical high-level lesions and cancer. Results: Experiments showed that our segmentation model had better diagnosis efficiency than colposcopic experts and other artificial intelligence models, and reached Accuracy of 93.29 %, Precision of 87.2 %, Specificity of 90.1 %, and mIoU of 80.27 %, respectively. Conclution: The DeepLabv3+ model had good performance in the segmentation of cervical lesions in colposcopic post-acetic-acid images and can better assist colposcopists in improving the diagnosis.

The Van der Waals-like phase transition is observed in temperature–thermal entropy plane in spherically symmetric charged Gauss–Bonnet–AdS black hole background. In terms of AdS/CFT, the non-local observables such as holographic entanglement entropy, Wilson loop, and two point correlation function of very heavy operators in the field theory dual to spherically symmetric charged Gauss–Bonnet–AdS black hole have been investigated. All of them exhibit the Van der Waals-like phase transition for a fixed charge parameter or Gauss–Bonnet parameter in such gravity background. Further, with choosing various values of charge or Gauss–Bonnet parameter, the equal area law and the critical exponent of the heat capacity are found to be consistent with phase structures in temperature–thermal entropy plane.

Phase structure of the quintessence Reissner–Nordström–AdS black hole is probed by the nonlocal observables such as holographic entanglement entropy and two point correlation function. Our result shows that, as the case of the thermal entropy, both the observables exhibit the Van der Waals-like phase transition. To reinforce this conclusion, we further check the equal area law for the first order phase transition and critical exponent of the heat capacity for the second order phase transition. We also discuss the effect of the state parameter on the phase structure of the nonlocal observables.

The phase structure of holographic entanglement entropy is studied in massive gravity for the quantum systems with finite and infinite volumes, which in the bulk is dual to calculating the minimal surface area for a black hole and black brane respectively. In the entanglement entropy–temperature plane, we find for both the black hole and black brane there is a Van der Waals-like phase transition as the case in thermal entropy–temperature plane. That is, there is a first order phase transition for the small charge and a second order phase transition at the critical charge. For the first order phase transition, the equal area law is checked and for the second order phase transition, the critical exponent of the heat capacity is obtained. All the results show that the phase structure of holographic entanglement entropy is the same as that of thermal entropy regardless of the volume of the spacetime on the boundary.

In a recent paper, arXiv:1309.4877, a holographic p-wave model has been proposed in an Einstein–Maxwell-complex vector field theory with a negative cosmological constant. The model exhibits rich phase structure depending on the mass and the charge of the vector field. We investigate the behavior of the entanglement entropy of dual field theory in this model. When the above two model parameters change, we observe the second order, first order and zeroth order phase transitions from the behavior of the entanglement entropy at some intermediate temperatures. These imply that the entanglement entropy can indicate not only the occurrence of the phase transition, but also the order of the phase transition. The entanglement entropy is indeed a good probe to phase transition. Furthermore, the “retrograde condensation” which is a sub-dominated phase is also reflected on the entanglement entropy.

From the viewpoint of holography, the phase structure of a 5-dimensional Reissner-Nordström-AdS black hole is probed by the two-point correlation function, Wilson loop, and entanglement entropy. As the case of thermal entropy, we find for all the probes that the black hole undergoes a Hawking-Page phase transition, a first-order phase transition, and a second-order phase transition successively before it reaches a stable phase. In addition, for these probes, we find that the equal area law for the first-order phase transition is valid always and the critical exponent of the heat capacity for the second-order phase transition coincides with that of the mean field theory regardless of the size of the boundary region.

Loop quantum cosmology (LQC) is very powerful to deal with the behavior of early universe. Moreover, the effective loop quantum cosmology gives a successful description of the universe in the semiclassical region. We consider the apparent horizon of the Friedmann-Robertson-Walker universe as a thermodynamical system and investigate the thermodynamics of LQC in the semiclassical region. The effective density and effective pressure in the modified Friedmann equation from LQC not only determine the evolution of the universe in LQC scenario but also are actually found to be the thermodynamic quantities. This result comes from the energy definition in cosmology (the Misner-Sharp gravitational energy) and is consistent with thermodynamic laws. We prove that within the framework of loop quantum cosmology, the elementary equation of equilibrium thermodynamics is still valid.

Objective: The objective of this study was to explore the clinical value of brainstem auditory evoked potential (BAEP) in the diagnosis of vertebrobasilar ischemia (VBI). Methods: The subjects were divided into the 2 following groups: an observation group of 300 VBI patients and a control group of 100 normal healthy volunteers. BAEP examination was carried out in both groups, and then the results were analyzed and compared. Results: BAEP abnormalities were observed in 59% (177 out of 300) of the patients in the observation group: brainstem type 64.4% (114 cases), inner-ear type 7.4% (13 cases), and mixed type 28.2% (50 cases). In the control group, abnormalities were observed in only 9% (9 cases): inner-ear type 66.7% (6 cases) and mixed type 33.3% (3 cases). There was a statistically significant difference between the 2 groups in their total abnormality rates (p < 0.05). After the neck twisting test, the BAEP abnormality rate of the observation group rose to 85% (255 cases) and was significantly different from that of normal BAEP (p < 0.05). Conclusion: BAEP is an easy but effective auxiliary means for the noninvasive examination of VBI with a high positive rate, thus providing objective evidence for the diagnosis of VBI that may be useful in future clinical application. © 2015 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

We continue to study the holographic p-wave superconductor model in the Einstein-Maxwell-complex vector field theory with a non-minimal coupling between the complex vector field and the Maxwell field. In this paper we work in the AdS soliton background which describes a conformal field theory in the confined phase and focus on the probe approximation. We find that an applied magnetic field can lead to the condensate of the vector field and the AdS soliton instability. As a result, a vortex lattice structure forms in the spatial directions perpendicular to the applied magnetic field. As a comparison, we also discuss the vector condensate in the Einstein-SU(2) Yang-Mills theory and find that in the setup of the present paper, the Einstein-Maxwell-complex vector field model is a generalization of the SU(2) model in the sense that the vector field has a general mass and gyromagnetic ratio. [ABSTRACT FROM AUTHOR]

We study a holographic p-wave superconductor model in a four dimensional Einstein-Maxwell-complex vector field theory with a negative cosmological constant. The complex vector field is charged under the Maxwell field. We solve the full coupled equations of motion of the system and find black hole solutions with the vector hair. The vector hairy black hole solutions are dual to a thermal state with the U(1) symmetry as well as the spatial rotational symmetry broken spontaneously. Depending on two parameters, the mass and charge of the vector field, we find a rich phase structure: zeroth order, first order and second order phase transitions can happen in this model. We also find "retrograde condensation" in which the hairy black hole solution exists only for the temperatures above a critical value with the free energy much larger than the one of the black hole without the vector hair. We construct the phase diagram for this system in terms of the temperature and charge of the vector field. [ABSTRACT FROM AUTHOR]

Virus reservoirs can persist in human immunodeficiency virus type 1 (HIV-1)-infected subjects despite effective plasma virus suppression. To compare viral dynamics in the absence and presence of antiretroviral therapy, blood mononuclear cells from 19 subjects with high plasma RNA levels and 18 subjects following prolonged virus suppression were examined, by use of in situ hybridization, to detect virus RNA expression before and after in vitro T cell activation. This approach reveals circulating lymphocytes expressing HIV-1 RNA before activation and an increase in cells with detectable HIV-1 RNA transcription after in vitro activation. The frequencies of these 2 cell populations are strongly correlated with plasma virus load and appear to be stable once a new steady state is established during therapy. The frequency of viral RNA-positive cells is equivalent to the frequency of cells that produce infectious virus. Thus, in HIV-1-infected subjects there are distinct virus reservoirs comprising both latent and replication-active cells. [ABSTRACT FROM AUTHOR]

Holographic thermalization for a black hole surrounded by phantom dark energy is probed. The result shows that the smaller the phantom dark energy parameter is, the easier the is plasma to thermalize as the chemical potential is fixed, the larger the chemical potential is, and the harder the plasma is to thermalize as the dark energy parameter is fixed. The thermalization velocity and thermalization acceleration are presented by fitting the thermalization curves. [ABSTRACT FROM AUTHOR]

Aim: To explore the mechanism of action of gypenosides (GPs) on type 2 diabetes mellitus and non-alcoholic fatty liver disease (T2DM-NAFLD) in rats., Methods: Sixty rats were randomly divided into a healthy group, an untreated disease model group and GP-treatment groups. The study involved the evaluation of biochemical parameters, including serum aspartate transaminase (AST), alanine transferase (ALT), blood glucose (BG), triglycerides (TG) and total cholesterol (TC). Additionally, the protective effect of the treatments were confirmed histopathologically and the expression of TNF-α and NF-κB in the rat liver was analyzed using immunohistochemistry. The expression of proliferator-activated receptor gamma (PPARγ) and cytochrome P450 (CYP450) 1A1 mRNA was determined by quantitative RT-PCR., Results: GP treatments at oral doses of 200, 400, and 800 mg/kg per day significantly decreased the levels of serum AST and ALT (P<0.05, P<0.01), especially at the dose of 800 mg/kg per day. To a similar extent, GP at 800 mg/kg per day reduced the levels of BG (4.19±0.47, P<0.01), TG (80.08±10.05, P<0.01), TC (134.38±16.39, P<0.01) and serum insulin (42.01±5.04, P<0.01). The expression of TNF-α and NF-κB measured by immunohistochemistry was significantly reduced by GPs in a dose-dependent manner, and the expression of PPARγ and CYP4501A1 mRNA, as measured using quantitative real-time PCR, were significantly down-regulated by GPs. Moreover, GPs decreased the infiltration of liver fats and reversed the histopathological changes in a dose-dependent manner., Conclusion: This study suggests that GPs have a protective effect against T2DM-NAFLD by down-regulating the expression of TNF-α and NF-κB proteins, and PPARγ and CYP4501A1 mRNAs.