105 research outputs found
Translating Solutions of a Generalized Mean Curvature Flow in a Cylinder: I. Constant Boundary Angles
We study a generalized mean curvature flow involving a positive power of the
mean curvature and a driving force. In this paper, we first construct all kinds
of radially symmetric translating solutions, and then select one of them to
satisfy a prescribed boundary angle in a cylinder. We then consider the flow
starting at an initial hypersurface: showing the a priori estimates (especially
the uniform-in-time bounds for the mean curvature which guarantee the uniform
parabolicity of the corresponding fully nonlinear equation), giving the global
existence for the solution of the initial boundary value problem, and proving
its convergence to the corresponding translating solution. Our study provides a
complete exposition on the influence of the dimension, the power of the mean
curvature, the driving force and the boundary angles on the existence and
stability of radially symmetric translating solutions.Comment: 29 page
A Mean Curvature Flow Propagating in a Cylinder at Exponential Speed
In this paper, we study the long time behaviour of mean curvature flow in a
cylinder with Robin boundary conditions. Such a boundary condition can force
the solution to have a singular behaviour at the boundary when .
The planar version of this problem has been investigated in an existing
literature, where the curve shortening flow in -dimensional band with Robin
boundary conditions is shown to converge to a translating Grim Reaper with
finite speed and fixed profile. By considering a radially symmetric mean
curvature flow, denoted by , in -dimensional cylinder (), we find in the present paper a new feature of the flow: both the interior
gradients and the propagating speed of the flow increase to infinity
exponentially, and as
for some , which is completely different from the
2-dimensional case
Convergence to the Grim Reaper for a Curvature Flow with Unbounded Boundary Slopes
We consider a curvature flow in the band domain , where, for a graphic curve , denotes its normal velocity and
denotes its curvature. If contacts the two boundaries
of with constant slopes, in 1993, Altschular and
Wu \cite{AW1} proved that converges to a {\it grim reaper}
contacting with the same prescribed slopes. In this paper
we consider the case where contacts with
slopes equaling to times of its height. When the curve moves to
infinity, the global gradient estimate is impossible due to the unbounded
boundary slopes. We first consider a special symmetric curve and derive its
uniform interior gradient estimates by using the zero number argument, and then
use these estimates to present uniform interior gradient estimates for general
non-symmetric curves, which lead to the convergence of the curve in
topology to the {\it grim reaper} with span
G2PTL: A Pre-trained Model for Delivery Address and its Applications in Logistics System
Text-based delivery addresses, as the data foundation for logistics systems,
contain abundant and crucial location information. How to effectively encode
the delivery address is a core task to boost the performance of downstream
tasks in the logistics system. Pre-trained Models (PTMs) designed for Natural
Language Process (NLP) have emerged as the dominant tools for encoding semantic
information in text. Though promising, those NLP-based PTMs fall short of
encoding geographic knowledge in the delivery address, which considerably trims
down the performance of delivery-related tasks in logistic systems such as
Cainiao. To tackle the above problem, we propose a domain-specific pre-trained
model, named G2PTL, a Geography-Graph Pre-trained model for delivery address in
Logistics field. G2PTL combines the semantic learning capabilities of text
pre-training with the geographical-relationship encoding abilities of graph
modeling. Specifically, we first utilize real-world logistics delivery data to
construct a large-scale heterogeneous graph of delivery addresses, which
contains abundant geographic knowledge and delivery information. Then, G2PTL is
pre-trained with subgraphs sampled from the heterogeneous graph. Comprehensive
experiments are conducted to demonstrate the effectiveness of G2PTL through
four downstream tasks in logistics systems on real-world datasets. G2PTL has
been deployed in production in Cainiao's logistics system, which significantly
improves the performance of delivery-related tasks
miRNA Expression Profile and Effect of Wenxin Granule in Rats with Ligation-Induced Myocardial Infarction
Wenxin Granule (WXKL) is a traditional Chinese medicine used for treatment of myocardial infarction (MI) and arrhythmias. However, the genomic pathological mechanisms of MI and mechanisms of WXKL are largely unknown. This study aims to investigate a comprehensive miRNA expression profile, and the predicted correlation pathways to be targeted by differentially expressed miRNAs in MI, and mechanisms of WXKL from a gene level. MI rat model was established by a coronary artery ligation surgery. miRNA expression microarrays were performed and the data were deposited in Gene Expression Omnibus (GEO number GSE95855). And, pathway analysis was performed by using the DIANA-miRPath v3.0 online tool. The expressions of miR-1, miR-133, Cx43, and Cx45 were detected by quantitative real-time PCR. It was found that 35 differentially expressed miRNAs and 23 predicted pathways, including miR-1, miR-133, and gap junction pathway, are involved in the pathogenesis of MI. And, WXKL increased the expressions of miR-1 and miR-133, while also increased the mRNA levels of Cx43 and Cx45, and, especially, recovered the Cx43/Cx45 ratio near to normal level. The results suggest that regulatory effects on miR-1, miR-133, Cx43, and Cx45 might be a possible mechanism of WXKL in the treatment of MI at the gene level
Global research of artificial intelligence in strabismus: a bibliometric analysis
PurposeTo analyze the global publications on artificial intelligence (AI) in strabismus using a bibliometric approach.MethodsThe Web of Science Core Collection (WoSCC) database was used to retrieve all of the publications on AI in strabismus from 2002 to 2023. We analyzed the publication and citation trend and identified highly-cited articles, prolific countries, institutions, authors and journals, relevant research domains and keywords. VOSviewer (software) and Bibliometrix (package) were used for data analysis and visualization.ResultsBy analyzing a total of 146 relevant publications, this study found an overall increasing trend in the number of annual publications and citations in the last decade. USA was the most productive country with the closest international cooperation. The top 3 research domains were Ophthalmology, Engineering Biomedical and Optics. Journal of AAPOS was the most productive journal in this field. The keywords analysis showed that “deep learning” and “machine learning” may be the hotspots in the future.ConclusionIn recent years, research on the application of AI in strabismus has made remarkable progress. The future trends will be toward optimized technology and algorithms. Our findings help researchers better understand the development of this field and provide valuable clues for future research directions
The Correlation between High-Sensitivity C-Reactive Protein, Matrix Metallopeptidase 9, and Traditional Chinese Medicine Syndrome in Patients with Hypertension
Hypertension is a common disease affecting millions of people throughout the world. Currently, there is a growing interest in the traditional Chinese medicine (TCM) for patients with hypertension mainly due to the personalized therapy of TCM in many countries. Clinical treatment of patients relies on the successful differentiation of a specific TCM syndrome for hypertension. However, it is difficult to understand that TCM syndrome classifications depend on the clinical experience of a TCM practitioner. Therefore, discovering an objective biomarker associated with TCM syndrome may be beneficial for TCM syndrome classifications. This paper focused on high sensitivity C-reactive protein (HCRP), matrix metallopeptidase 9 (MMP9), and TCM syndrome, and aimed to investigate the relationships between TCM syndrome and the two inflammatory biomarkers in patients with essential hypertension. The result showed that both HCRP and MMP9 are positively correlated with syndrome of wind and phlegm turbidity. Detection of the serum levels of HCRP and MMP9 is beneficial for TCM syndrome classification and prediction of cardiovascular and cerebrovascular risk events in hypertensive patients
Effects of Wenxin Keli on the Action Potential and L-Type Calcium Current in Rats with Transverse Aortic Constriction-Induced Heart Failure
Objective. We investigated the effects of WXKL on the action potential (AP) and the L-type calcium current (ICa-L) in normal and hypertrophied myocytes. Methods. Forty male rats were randomly divided into two groups: the control group and the transverse aortic constriction- (TAC-) induced heart failure group. Cardiac hypertrophy was induced by TAC surgery, whereas the control group underwent a sham operation. Eight weeks after surgery, single cardiac ventricular myocytes were isolated from the hearts of the rats. The APs and ICa-L were recorded using the whole-cell patch clamp technique. Results. The action potential duration (APD) of the TAC group was prolonged compared with the control group and was markedly shortened by WXKL treatment in a dose-dependent manner. The current densities of the ICa-L in the TAC group treated with 5 g/L WXKL were significantly decreased compared with the TAC group. We also determined the effect of WXKL on the gating mechanism of the ICa-L in the TAC group. We found that WXKL decreased the ICa-L by accelerating the inactivation of the channels and delaying the recovery time from inactivation. Conclusions. The results suggest that WXKL affects the AP and blocked the ICa-L, which ultimately resulted in the treatment of arrhythmias
Qingkailing Suppresses the Activation of BV2 Microglial Cells by Inhibiting Hypoxia/Reoxygenation-Induced Inflammatory Responses
Qingkailing (QKL) is a well-known composite extract used in traditional Chinese medicine. This extract has been extensively administered to treat the acute phase of cerebrovascular disease. Our previous experiments confirmed that QKL exerts an inhibitory effect on cerebral ischemia-induced inflammatory responses. However, whether QKL suppresses the activation of microglia, the primary resident immune cells in the brain, has yet to be determined. In this study, BV2 microglial cells were used to validate the protective effects of QKL treatment following ischemia-reperfusion injury simulated via hypoxia/reoxygenation in vitro. Under these conditions, high expression levels of ROS, COX-2, iNOS, and p-p38 protein were detected. Following ischemia/reperfusion injury, QKL significantly increased the activity of BV2 cells to approximately the basal level by modulating microglial activation via inhibition of inflammatory factors, including TNF-α, COX-2, iNOS, and p-p38. However, QKL treatment also displayed dose-dependent differences in its inhibitory effects on p38 phosphorylation and inflammatory factor expression
Qingkailing Suppresses the Activation of BV2 Microglial Cells by Inhibiting Hypoxia/Reoxygenation-Induced Inflammatory Responses
Qingkailing (QKL) is a well-known composite extract used in traditional Chinese medicine. This extract has been extensively administered to treat the acute phase of cerebrovascular disease. Our previous experiments confirmed that QKL exerts an inhibitory effect on cerebral ischemia-induced inflammatory responses. However, whether QKL suppresses the activation of microglia, the primary resident immune cells in the brain, has yet to be determined. In this study, BV2 microglial cells were used to validate the protective effects of QKL treatment following ischemia-reperfusion injury simulated via hypoxia/reoxygenation in vitro. Under these conditions, high expression levels of ROS, COX-2, iNOS, and p-p38 protein were detected. Following ischemia/reperfusion injury, QKL significantly increased the activity of BV2 cells to approximately the basal level by modulating microglial activation via inhibition of inflammatory factors, including TNF-, COX-2, iNOS, and p-p38. However, QKL treatment also displayed dosedependent differences in its inhibitory effects on p38 phosphorylation and inflammatory factor expression
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