arXiv subjects

Guoli Liu

Publications and source records attributed to Guoli Liu.

16 recordsLinked to original sources

arXiv2025

Artificial Intelligence-derived Cardiotocography Age as a Digital Biomarker for Predicting Future Adverse Pregnancy Outcomes

Cardiotocography (CTG) is a low-cost, non-invasive fetal health assessment technique used globally, especially in underdeveloped countries. However, it is currently mainly used to identify the fetus's current status (e.g., fetal acidosis or hypoxia), and the potential of CTG in predicting future adverse pregnancy outcomes has not been fully explored. We aim to develop an AI-based model that predicts biological age from CTG time series (named CTGage), then calculate the age gap between CTGage and actual age (named CTGage-gap), and use this gap as a new digital biomarker for future adverse pregnancy outcomes. The CTGage model is developed using 61,140 records from 11,385 pregnant women, collected at Peking University People's Hospital between 2018 and 2022. For model training, a structurally designed 1D convolutional neural network is used, incorporating distribution-aligned augmented regression technology. The CTGage-gap is categorized into five groups: < -21 days (underestimation group), -21 to -7 days, -7 to 7 days (normal group), 7 to 21 days, and > 21 days (overestimation group). We further defined the underestimation group and overestimation group together as the high-risk group. We then compare the incidence of adverse outcomes and maternal diseases across these groups. The average absolute error of the CTGage model is 10.91 days. When comparing the overestimation group with the normal group, premature infants incidence is 5.33% vs. 1.42% (p < 0.05) and gestational diabetes mellitus (GDM) incidence is 31.93% vs. 20.86% (p < 0.05). When comparing the underestimation group with the normal group, low birth weight incidence is 0.17% vs. 0.15% (p < 0.05) and anaemia incidence is 37.51% vs. 34.74% (p < 0.05). Artificial intelligence-derived CTGage can predict the future risk of adverse pregnancy outcomes and hold potential as a novel, non-invasive, and easily accessible digital biomarker.

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arXiv2025

Simultaneous Polysomnography and Cardiotocography Reveal Temporal Correlation Between Maternal Obstructive Sleep Apnea and Fetal Hypoxia

Background: Obstructive sleep apnea syndrome (OSAS) during pregnancy is common and can negatively affect fetal outcomes. However, studies on the immediate effects of maternal hypoxia on fetal heart rate (FHR) changes are lacking. Methods: We used time-synchronized polysomnography (PSG) and cardiotocography (CTG) data from two cohorts to analyze the correlation between maternal hypoxia and FHR changes (accelerations or decelerations). Maternal hypoxic event characteristics were analyzed using generalized linear modeling (GLM) to assess their associations with different FHR changes. Results: A total of 118 pregnant women participated. FHR changes were significantly associated with maternal hypoxia, primarily characterized by accelerations. A longer hypoxic duration correlated with more significant FHR accelerations (P < 0.05), while prolonged hypoxia and greater SpO2 drop were linked to FHR decelerations (P < 0.05). Both cohorts showed a transient increase in FHR during maternal hypoxia, which returned to baseline after the event resolved. Conclusion: Maternal hypoxia significantly affects FHR, suggesting that maternal OSAS may contribute to fetal hypoxia. These findings highlight the importance of maternal-fetal interactions and provide insights for future interventions.

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arXiv2011

The charged top-pion production associated with the bottom quark pair as a probe of the topcolor-assisted technicolor model at the LHC

The topcolor-assisted technicolor (TC2) model predicts the existence of the charged top-pions ($π_t^\pm$), whose large couplings with the third generation fermions will induce the charged top-pion production associated with the bottom and anti-bottom quark pair at the CERN Large Hadron Collider (LHC) through the parton processes $c\bar b \to π_t^+ b \bar b$ and $u\bar d(c\bar s) \to π_t^+ b \bar b$. In this paper we examine these productions and find that, due to the small Standard Model backgrounds, their production rates can exceed the $3σ$ sensitivity of the LHC in a large part of parameter space, so these processes may serve as a good probe for the TC2 model.

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arXiv2007

Single top production associated with a neutral scalar at LHC in topcolor-assisted technicolor

The topcolor-assisted technicolor (TC2) model predicts a number of neutral scalars like the top-pion ($π^0_t$) and the top-Higgs ($h^0_t$). These scalars have flavor-changing neutral-current (FCNC) top quark couplings, among which the top-charm transition couplings may be sizable. Such FCNC couplings induce single top productions associated with a neutral scalar at the CERN Large Hadron Collider (LHC) through the parton processes $cg \to t π_t^0$ and $cg \to t h_t^0$. In this note we examine these productions and find their production rates can exceed the $3σ$ sensitivity of the LHC in a large part of parameter space. Since in the Standard Model and the minimal supersymmetric model such rare productions have unobservably small production rates at the LHC, these rare processes will serve as a good probe for the TC2 model.

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arXiv2007

Top-quark FCNC Productions at LHC in Topcolor-assisted Technicolor Model

We evaluate the top-quark FCNC productions induced by the topcolor assisted technicolor (TC2) model at the LHC. These productions proceed respectively through the parton-level processes g g -> t c_bar, c g->t, c g -> t g, c g -> t Z and c g -> t γ. We show the dependence of the production rates on the relevant TC2 parameters and compare the results with the predictions in the minimal supersymmetric model. We find that for each channel the TC2 model predicts a much larger production rate than the supersymmetric model. All these rare productions in the TC2 model can be enhanced above the 3-sigma sensitivity of the LHC. Since in the minimal supersymmetric model only c g -> t is slightly larger than the corresponding LHC sensitivity, the observation of these processes will favor the TC2 model over the supersymmetric model. In case of unobservation, the LHC can set meaningful constraints on the TC2 parameters.

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arXiv2005

Probing New Physics from Top-charm Associated Productions at Linear Colliders

The top-charm associated productions via $e^+ e^-$, $e^- γ$ and $γγ$ collisions at linear colliders, which are extremely suppressed in the Standard Model (SM), could be significantly enhanced in some extensions of the SM. In this article we calculate the full contribution of the topcolor-assisted technicolor (TC2) to these productions and then compare the results with the existing predictions of the SM, the general two-Higgs-doublet model and the Minimal Supersymmetric Model. We find that the TC2 model predicts much larger production rates than other models and the largest-rate channel is $γγ\to t \bar{c}$, which exceeds 10 fb for a large part of the parameter space. From the analysis of the observability of such productions at the future linear colliders, we find that the predictions of the TC2 model can reach the observable level for a large part of the parameter space while the predictions of other models are hardly accessible.

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arXiv2004

Probing Topcolor-Assisted Technicolor from Like-sign Top Pair Production at LHC

The topcolor-assisted technicolor (TC2) theory predicts tree-level flavor-changing neutral-current (FCNC) top quark Yukawa couplings with top-pions. Such FCNC interactions will induce like-sign top quark pair productions at CERN Large Hadron Collider (LHC). While these rare productions are far below the observable level in the Standard Model and other popular new physics models such as the Minimal Supersymmetric Model, we find that in a sound part of parameter space the TC2 model can enhance the production cross sections to several tens of fb and thus may be observable at the LHC due to rather low backgrounds. Searching for these productions at the LHC will serve as an excellent probe for the TC2 model.

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arXiv2001

The process $e^{+}e^{-}\to \bar{t}c$ in topcolor-assisted technicolor models

We consider the flavor changing neutral current(FCNC) process $e^{+}e^{-}\to\bar{t}c$(or $t\bar{c}$) in the context of topcolor-assisted technicolor(TC2) models. We find that the contributions of charged scalars (technipions and top-pions) and topcolor gauge bosons are negligibly small. The neutral scalars (top-pion $π_{t}^{0}$ and top-Higgs $h_{t}^{0}$) can give significant contributions to this process. With reasonable values of the parameters in TC2 models, there will be several tens of the observable $\bar{t}c$ events to be generated in the future $e^{+}e^{-}$ linear colliders.

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arXiv2001

Lepton-Flavor Violating Processes $l_{i}\to l_{j}γ$ in Topcolor Assisted Technicolor Models

We consider the lepton-flavor violating(LFV) processes $l_{i}\to l_{j}γ$ in the framework of topcolor assisted technicolor(TC2) models. We find that the new gauge boson $Z^{\prime}$ predicted by TC2 models can give significantly contributions to these processes via the flavor changing couplings. The present experimental bound on the LFV process $μ\to eγ$ gives severe constraints on the TC2 models. In the case that the $Z^{\prime}$ mass $M_{Z}$ is consistent with other experimental constraints, we obtain constraints on the lepton mixing factors $K_{τμ}$ and $K_{τe}$. The future LFV experiments will be probe of the TC2 models.

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arXiv2001

The rare top decay $t\to c g$ in topcolor assisted technicolor models

In the framework of topcolor-assisted technicolor(TC2) models, we calculate the contributions of flavor changing scalar couplings involved the neutral top-pion $π_{t}^{0}$ and top-Higgs $h_{t}^{0}$ to the branching ratio $B_{r}(t\longrightarrow cg)$. We find that the value of $B_{r}(t\longrightarrow cg)$ can reach $ 1\times10^{-3}$ with reasonable values of the parameters in TC2 models, which may be testable in the future experiments.

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arXiv2001

Topcolor assisted technicolor models and muon anomalous magnetic moment

We discuss and estimate the contributions of the new particles predicted by topcolor assisted technicolor(TC2) models to the muon anomalous magnetic moment $a_μ$. Our results show that the contributions of Pseudo Goldstone bosons are very small which can be safely ignored. The main contributions come from the ETC gauge boson $x_μ$ and topcolor gauge boson $Z^{\prime}$. If we demand that the mass of $Z^{\prime}$ is consistent with other experimental constrains, its contributions are smaller than that of $x_μ$. With reasonable values of the parameters in TC2 models, the observed BNL results for $a_μ$ could be explained.

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arXiv2001

Detecting top-Higgs at high energy $e^{+}e^{-}$ colliders

We calculate the contributions of the top-Higgs $h_{t}^{0}$ predicted by topcolor assisted technicolor(TC2) models to $e^{+}e^{-}\longrightarrow \overline{t}c\overlineν_{e}ν_{e}$ and compare the results with the contributions of $h^{0}_{t}$ to the processes $e^{+}e^{-}\longrightarrow Z h^{0}_{t}\longrightarrow Z\overline{t}c$ and $e^+e^-\longrightarrow γh^{0}_{t} \longrightarrow γ\overline{t}c$. We find that $e^{+}e^{-} \longrightarrow\overline{t}c\overlineν_{e}ν_{e}$ is very sensitive to $h^{0}_{t}$, which can be easy detected via this process at high-energy $e^{+}e^{-}$ collider(LC) experiments with $\sqrt{s}\geq 500$ $GeV$, as long as its mass below the $\overline{t}t$ threshold. The process $e^{+}e^{-} \longrightarrow γ\overline{t}c$ also can be used to detect $h^{0}_{t}$ at LC experiments.

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arXiv2001

The flavor-changing rare top decays $t\to c V V$ in topcolor-assisted technicolor theory

In the framework of topcolor-assisted technicolor (TC2) theory, we calculate the contributions of the scalars(the neutral top-pion $π_{t}^{0}$ and the top-Higgs $h_{t}^{0}$) to the flavor-changing rare top decays $t\to c V V$(V= W, g, $γ$ or Z). Our results show that $h_{t}^{0}$ can enhance the standard model $B_{r}^{SM}(t\longrightarrow cWW)$ by several orders of magnitude for most of the parameter space. The peak of the branching ratio resonance emerges when the top-Higgs mass is between $2m_{W}$ and $m_{t}$. The branching ratio $ B_{r}(t\to c W W)$ can reach $ 10^{-3}$ in the narrow range.

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arXiv2000

Production and decay of the neutral top-pion in high energy $e^{+}e^{-}$ colliders

We study the production and decay of the neutral top-pion $π_{t}^{0}$ predicted by topcolor-assisted technicolor(TC2) theory. Our results show that, except the dominant decay modes $b\bar{b}$, $\bar{t}c$ and $gg$, the $π_{t}^{0}$ can also decay into $γγ$ and $Z γ$ modes. It can be significantly produced at high energy $e^{+}e^{-}$ collider(LC) experiments via the processes $e^{+}e^{-}\to π_{t}^{0}γ$ and $e^{+}e^{-}\to Zπ_{t}^{0}$. We further calculate the production cross sections of the processes $e^{+}e^{-}\toγπ_{t}^{0}\toγ\bar{t}c$ and $e^{+}e^{-}\to Zπ_{t}^{0}\to Z\bar{t}c$. We find that the signatures of the neutral top-pion $π_{t}^{0}$ can be detected via these processes.

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arXiv2000

The bound on the mass of the new gauge boson $Z^{\prime}$ from the process $μ\longrightarrow 3e$

The new gauge boson $Z^{\prime}$ predicted by the strong top dynamical symmetry breaking models has significant contributions to the lepton flavor changing process $μ\longrightarrow 3e $. We consider the bound on the mass of the new gauge boson $Z^{\prime}$ from the experimental value of the branching ratio $Br(μ\longrightarrow 3e)$ in the framework of topcolor assisted technicolor models. We find that the precision experimental value of $Br(μ\longrightarrow 3e)$ gives a severe bound on the $Z^{\prime}$ mass $M_{Z^{\prime}}$. For $k_1 \leq 1$, $M_{Z^{\prime}}$ must be larger than 1.64 $TeV$.

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arXiv2000

Neutral top-pion and top-charm production in high energy $e^{+}e^{-}$ collisions

We calculate the contributions of the neutral top-pion, predicted by topcolor-assisted technicolor (TC2) theory, to top-charm production via the processes $γγ\longrightarrow\bar{t}c$ and $e^{+}e^{-}\longrightarrow γγ\longrightarrow \bar{t}c$ at the high energy linear $e^{+}e^{-}$ collider (LC) experiments. The cross section is of order $10^{-2}pb$ in most of the parameter space of TC2 theory, which may be detected at the LC experiments. So the process $e^{+}e^{-}\longrightarrow \bar{t}c$ can be used to detect the signature of TC2 theory.

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