Search

Your search keyword '"Qi, Weiwei"' showing total 860 results
Start Over Author "Qi, Weiwei"
860 results on '"Qi, Weiwei"'

1. CU-Net: a U-Net architecture for efficient brain-tumor segmentation on BraTS 2019 dataset

Author

Zhang, Qimin, Qi, Weiwei, Zheng, Huili, and Shen, Xinyu

Subjects
Computer Science - Computer Vision and Pattern Recognition, Computer Science - Artificial Intelligence, Quantitative Biology - Neurons and Cognition
Abstract

Accurately segmenting brain tumors from MRI scans is important for developing effective treatment plans and improving patient outcomes. This study introduces a new implementation of the Columbia-University-Net (CU-Net) architecture for brain tumor segmentation using the BraTS 2019 dataset. The CU-Net model has a symmetrical U-shaped structure and uses convolutional layers, max pooling, and upsampling operations to achieve high-resolution segmentation. Our CU-Net model achieved a Dice score of 82.41%, surpassing two other state-of-the-art models. This improvement in segmentation accuracy highlights the robustness and effectiveness of the model, which helps to accurately delineate tumor boundaries, which is crucial for surgical planning and radiation therapy, and ultimately has the potential to improve patient outcomes.

Published
2024

2. Harnessing XGBoost for Robust Biomarker Selection of Obsessive-Compulsive Disorder (OCD) from Adolescent Brain Cognitive Development (ABCD) data

Author

Shen, Xinyu, Zhang, Qimin, Zheng, Huili, and Qi, Weiwei

Subjects
Quantitative Biology - Neurons and Cognition, Computer Science - Machine Learning, Statistics - Applications
Abstract

This study evaluates the performance of various supervised machine learning models in analyzing highly correlated neural signaling data from the Adolescent Brain Cognitive Development (ABCD) Study, with a focus on predicting obsessive-compulsive disorder scales. We simulated a dataset to mimic the correlation structures commonly found in imaging data and evaluated logistic regression, elastic networks, random forests, and XGBoost on their ability to handle multicollinearity and accurately identify predictive features. Our study aims to guide the selection of appropriate machine learning methods for processing neuroimaging data, highlighting models that best capture underlying signals in high feature correlations and prioritize clinically relevant features associated with Obsessive-Compulsive Disorder (OCD).

Published
2024

5. Effect of different antibiotics combined with tigecycline in patients with multidrug-resistant Acinetobacter baumannii-related ventilator-associated pneumonia: A comparative study

Author

SHI Xinyan, SHANG Ning, WANG Hong, YANG Tingting, ZHAO Chunling, QI Weiwei, LIU Wei

Subjects
tigecycline, pneumonia, ventilator-associated, acinetobacter baumannii, drug resistance,bacterial, comparative effectiveness research, Medicine
Abstract

Objective To investigate the effect of different antibacterial agents combined with tigecycline in patients with multidrug-resistant Acinetobacter baumannii (MDRAB)-related ventilator-associated pneumonia (VAP), and to provide options for better treatment of the disease in clinical practice. Methods A retrospective analysis was performed for the clinical data of the patients with MDRAB-related VAP who were admitted from January 2016 to August 2023 in Qingdao municipal Hospital, and according to the treatment regimen, they were divided into tigecycline group (group A) with 56 patients, cefoperazone-sulbactam combination therapy group (B group) with 42 patients, and carbapenem combination therapy group (group C) with 24 patients. The three groups were compared in terms of infection and related outcome measures. Results There were no significant diffe-rences in the type of pathogene infected and infection sites between the three groups (P>0.05). Groups B and C had a significantly higher bacterial clearance rate than group A (χ2=5.38,4.48,P0.05). Conclusion Tigecycline combined with cefoperazone-sulbactam or carbapenem achieves a higher bacterial clearance rate than tigecycline alone in MDRAB-related VAP, and combined medication is a relatively good treatment option.

Published
2024
Full Text
View/download PDF

6. Inhibitory effect of daphnetin on gastric cancer cells and its mechanism

Author

ZHU Chunyang, ZHAO Shufen, WANG Yan, FANG Yuanyuan, ZHANG Siyi, QI Weiwei

Subjects
stomach neoplasms, daphnetin, autophagy, reactive oxygen species, membrane potential, mitochondrial, Medicine
Abstract

Objective To explore the inhibitory effect of daphnetin (Dap) on gastric cancer cells and its mechanism. Methods Gastric cancer AGS cells were treated with Dap at concentrations of 0, 30, 60, 90, 120, and 150 μmol/L, and the effect on cell viability was evaluated after 48 h using the MTT assay. AGS cells were divided into groups A to E, and each group was treated with Dap at concentrations of 0, 30, 60, 90, 120, and 150 μmol/L, respectively, for 48 h. Each group was observed for changes in cell count and morphology using optical microscopy and crystal violet staining. DCF staining was used to evaluate the effect of Dap on intracellular reactive oxygen species (ROS) levels in AGS cells in groups A to D, while JC-1 staining was used to evaluate the effect of Dap on the level of mitochondrial membrane potential (MMP) in AGS cells in groups A to D. Western blot was conducted to measure the expression levels of LC3 and P62 proteins in AGS cells in groups A to D, and changes in autophagic flux in AGS cells were measured by Ad-mCherry-GFP-LC3B staining. Results Dap significantly inhibited AGS cell viability in a concentration-dependent manner (F=321.50,t=12.44-34.77,P

Published
2024
Full Text
View/download PDF

15. Optimization Model for Bus Bay Stop Design Parameters Based on Trajectory Data

Author

Qi, Weiwei, Wang, Huapeng, Ruan, Lianjie, Shen, Bin, Angrisani, Leopoldo, Series Editor, Arteaga, Marco, Series Editor, Chakraborty, Samarjit, Series Editor, Chen, Jiming, Series Editor, Chen, Shanben, Series Editor, Chen, Tan Kay, Series Editor, Dillmann, Rüdiger, Series Editor, Duan, Haibin, Series Editor, Ferrari, Gianluigi, Series Editor, Ferre, Manuel, Series Editor, Jabbari, Faryar, Series Editor, Jia, Limin, Series Editor, Kacprzyk, Janusz, Series Editor, Khamis, Alaa, Series Editor, Kroeger, Torsten, Series Editor, Li, Yong, Series Editor, Liang, Qilian, Series Editor, Martín, Ferran, Series Editor, Ming, Tan Cher, Series Editor, Minker, Wolfgang, Series Editor, Misra, Pradeep, Series Editor, Mukhopadhyay, Subhas, Series Editor, Ning, Cun-Zheng, Series Editor, Nishida, Toyoaki, Series Editor, Oneto, Luca, Series Editor, Panigrahi, Bijaya Ketan, Series Editor, Pascucci, Federica, Series Editor, Qin, Yong, Series Editor, Seng, Gan Woon, Series Editor, Speidel, Joachim, Series Editor, Veiga, Germano, Series Editor, Wu, Haitao, Series Editor, Zamboni, Walter, Series Editor, Tan, Kay Chen, Series Editor, Wang, Wuhong, editor, Jin, Lisheng, editor, and Tan, Haiqiu, editor

Published
2024
Full Text
View/download PDF

16. Population dynamics under demographic and environmental stochasticity

Author

Hening, Alexandru, Qi, Weiwei, Shen, Zhongwei, and Yi, Yingfei

Subjects
Mathematics - Probability, Mathematics - Dynamical Systems, Mathematics - Spectral Theory, Quantitative Biology - Populations and Evolution, 35Q84, 35J25, 37B25, 60J60
Abstract

The present paper is devoted to the study of the long term dynamics of diffusion processes modelling a single species that experiences both demographic and environmental stochasticity. In our setting, the long term dynamics of the diffusion process in the absence of demographic stochasticity is determined by the sign of $\Lambda_0$, the external Lyapunov exponent, as follows: $\Lambda_0<0$ implies (asymptotic) extinction and $\Lambda_0>0$ implies convergence to a unique positive stationary distribution $\mu_0$. If the system is of size $\frac{1}{\epsilon^{2}}$ for small $\epsilon>0$ (the intensity of demographic stochasticity), demographic effects will make the extinction time finite almost surely. This suggests that to understand the dynamics one should analyze the quasi-stationary distribution (QSD) $\mu_\epsilon$ of the system. The existence and uniqueness of the QSD is well-known under mild assumptions. We look at what happens when the population size is sent to infinity, i.e., when $\epsilon\to 0$. We show that the external Lyapunov exponent still plays a key role: 1) If $\Lambda_0<0$, then $\mu_\epsilon\to \delta_0$, the mean extinction time is of order $|\ln \epsilon|$ and the extinction rate associated with the QSD $\mu_{\epsilon}$ has a lower bound of order $\frac{1}{|\ln\epsilon|}$; 2) If $\Lambda_0>0$, then $\mu_\epsilon\to \mu_0$, the mean extinction time is polynomial in $\frac{1}{\epsilon^{2}}$ and the extinction rate is polynomial in $\epsilon^{2}$. Furthermore, when $\Lambda_0>0$ we are able to show that the system exhibits multiscale dynamics: at first the process quickly approaches the QSD $\mu_\epsilon$ and then, after spending a polynomially long time there, it relaxes to the extinction state. We give sharp asymptotics in $\epsilon$ for the time spent close to $\mu_\epsilon$., Comment: 49 pages

Published
2022

19. Locoregional therapy combined with systemic therapy (LRT + ST) for unresectable and metastatic intrahepatic cholangiocarcinoma: a systematic review and meta-analysis

Author

Zhang Mengqi, Qi Weiwei, Qiu Xiaofei, Yu Chunpeng, Qiu Wensheng, Wang Song, and Qiu Zhenkang

Subjects
unresectable icca, locoregional therapy, systemic therapy, meta-analysis, Medical physics. Medical radiology. Nuclear medicine, R895-920
Abstract

The outcome of systemic therapy (ST) for unresectable and metastatic intrahepatic cholangiocarcinoma (iCCA) is poor. This study aims to further evaluate the efficacy and safety of locoregional therapy combined with systemic therapy (LRT + ST) compared with only ST in unresectable and metastatic iCCA by performing a systematic literature review and meta-analysis.

Published
2023
Full Text
View/download PDF

24. Quasi-stationary distributions of multi-dimensional diffusion processes

Author

Hening, Alexandru, Qi, Weiwei, Shen, Zhongwei, and Yi, Yingfei

Subjects
Mathematics - Probability, Mathematics - Analysis of PDEs, Mathematics - Spectral Theory, Quantitative Biology - Populations and Evolution, 60J60, 60J70, 34F05, 92D25, 60H10
Abstract

The present paper is devoted to the investigation of the long term behavior of a class of singular multi-dimensional diffusion processes that get absorbed in finite time with probability one. Our focus is on the analysis of quasi-stationary distributions (QSDs), which describe the long term behavior of the system conditioned on not being absorbed. Under natural Lyapunov conditions, we construct a QSD and prove the sharp exponential convergence to this QSD for compactly supported initial distributions. Under stronger Lyapunov conditions ensuring that the diffusion process comes down from infinity, we show the uniqueness of a QSD and the exponential convergence to the QSD for all initial distributions. Our results can be seen as the multi-dimensional generalization of Cattiaux et al (Ann. Prob. 2009) as well as the complement to Hening and Nguyen (Ann. Appl. Prob. 2018) which looks at the long term behavior of multi-dimensional diffusions that can only become extinct asymptotically. The centerpiece of our approach concerns a uniformly elliptic operator that we relate to the generator, or the Fokker-Planck operator, associated to the diffusion process. This operator only has singular coefficients in its zeroth-order terms and can be handled more easily than the generator. For this operator, we establish the discreteness of its spectrum, its principal spectral theory, the stochastic representation of the semigroup generated by it, and the global regularity for the associated parabolic equation. We show how our results can be applied to most ecological models, among which cooperative, competitive, and predator-prey Lotka-Volterra systems., Comment: 71 pages, 1 figure

Published
2021

25. Analysis of Key Technologies and Applications of Distributed Cooperative Countermeasure in Communication Countermeasure

Author

Qi, Weiwei, Lei, Mengda, Li, Xianlong, Wu, Hao, Fan, Jiangtao, Lu, LinPeng, Lei, Zhong, Angrisani, Leopoldo, Series Editor, Arteaga, Marco, Series Editor, Chakraborty, Samarjit, Series Editor, Chen, Jiming, Series Editor, Chen, Shanben, Series Editor, Chen, Tan Kay, Series Editor, Dillmann, Rüdiger, Series Editor, Duan, Haibin, Series Editor, Ferrari, Gianluigi, Series Editor, Ferre, Manuel, Series Editor, Jabbari, Faryar, Series Editor, Jia, Limin, Series Editor, Kacprzyk, Janusz, Series Editor, Khamis, Alaa, Series Editor, Kroeger, Torsten, Series Editor, Li, Yong, Series Editor, Liang, Qilian, Series Editor, Martín, Ferran, Series Editor, Ming, Tan Cher, Series Editor, Minker, Wolfgang, Series Editor, Misra, Pradeep, Series Editor, Mukhopadhyay, Subhas, Series Editor, Ning, Cun-Zheng, Series Editor, Nishida, Toyoaki, Series Editor, Oneto, Luca, Series Editor, Panigrahi, Bijaya Ketan, Series Editor, Pascucci, Federica, Series Editor, Qin, Yong, Series Editor, Seng, Gan Woon, Series Editor, Speidel, Joachim, Series Editor, Veiga, Germano, Series Editor, Wu, Haitao, Series Editor, Zamboni, Walter, Series Editor, Zhang, Junjie James, Series Editor, Tan, Kay Chen, Series Editor, Qian, Zhihong, editor, Jabbar, M.A., editor, Cheung, Simon K. S., editor, and Li, Xiaolong, editor

Published
2023
Full Text
View/download PDF

35. Plateaued CD4+ T count and its influencing factors in HIV infected patients after long-term antiviral treatment

Author

JIANG Haidong, YUAN Jing, QI Weiwei, HE Kun, YANG Honghong, and LIU Min

Subjects
human immunodeficiency virus, cd4+t cells, severe suboptimal immune responders, age, baseline, Medicine (General), R5-920
Abstract

Objective To investigate the plateaued count of CD4+ T cells in human immunodeficiency virus (HIV)-infected patients after long-term antiretroviral therapy (ART) and its influencing factors. Methods All HIV-infected patients receiving continuous ART for >8 years till December 2021 and with HIV RNA < 200 copies/mL in the Infection Department of Chongqing Public Health Medical Treatment Center were recruited and subjected as research object. Their age, ART scheme and CD4+ T count at each time point were collected retrospectively, the growth of CD4+ T count was counted, and the factors affecting CD4+ T count in the plateau stage were analyzed. Results A total of 766 patients who receiving ART for longer than 8 years were included in this study. The median plateaued count of CD4+ T cells was 394.0 (292.0, 507.0)/μL. There were 66 (8.6%) patients of suboptimal immune responders (SIR) with CD4+ T count < 200/μL, 458 (59.8%) with the count ≥350/μL, and 198 (25.8%) ≥500/μL. Based on baseline CD4+ T count (< 200, 200~349, 350~499, and ≥500/μL), the patients were divided into 4 groups and significant differences were seen in CD4+ T count and its increase from baseline in each group (P < 0.05). The teenager group had obviously higher plateaued count of CD4+T cells [403 (306, 519)/μL] than the middle-aged and elderly group (P < 0.05). Univariate analysis showed that the proportion of patients older than 44 years was notably larger (P < 0.01), and that of patients with baseline CD4+ T count < 100/μL was also higher (54.5% vs 17.6%, P < 0.05) in the severe SIR group than the non-severe SIR group. Multivariate analysis indicated that age over 44 years old (OR=2.061, 95%CI: 1.157~3.672) and baseline CD4+ T count < 100/μL (OR=4.803, 95%CI: 2.767~8.340) were associated with severe SIR in plateau stage (P < 0.05). Conclusion The plateaued count of CD4+ T cells in HIV-infected patients is generally low in plateau stage. In middle-aged and elderly patients, those with baseline CD4+ T count < 100/μL at initiation of ART is at higher risk for severe SIR in plateau stage. Early screening and early treatment are the key points to prevent and control the occurrence of severe SIR.

Published
2023
Full Text
View/download PDF

42. The novel role of Kallistatin in linking metabolic syndromes and cognitive memory deterioration by inducing amyloid-β plaques accumulation and tau protein hyperphosphorylation

Author

Qi, Weiwei, primary, Long, Yanlan, additional, Li, Ziming, additional, Zhao, Zhen, additional, Shi, Jinhui, additional, Xie, Wanting, additional, Wang, Laijian, additional, Tan, Yandan, additional, Zhou, Ti, additional, Jiang, Ping, additional, Jiang, Bin, additional, Yang, Xia, additional, and Gao, Guoquan, additional

Published
2024
Full Text
View/download PDF

46. The biosynthesis of storage reserves and auxin is coordinated by a hierarchical regulatory network in maize endosperm.

Author

Song, Teng, Huo, Qiang, Li, Chaobin, Wang, Qun, Cheng, Lijun, Qi, Weiwei, Ma, Zeyang, and Song, Rentao

Subjects
GENETIC regulation, BIOLOGICAL networks, CORN, TRANSCRIPTION factors, BIOSYNTHESIS
Abstract

Summary: Grain filling in maize (Zea mays) is intricately linked to cell development, involving the regulation of genes responsible for the biosynthesis of storage reserves (starch, proteins, and lipids) and phytohormones. However, the regulatory network coordinating these biological functions remains unclear.In this study, we identified 1744 high‐confidence target genes co‐regulated by the transcription factors (TFs) ZmNAC128 and ZmNAC130 (ZmNAC128/130) through chromatin immunoprecipitation sequencing coupled with RNA‐seq analysis in the zmnac128/130 loss‐of‐function mutants. We further constructed a hierarchical regulatory network using DNA affinity purification sequencing analysis of downstream TFs regulated by ZmNAC128/130.In addition to target genes involved in the biosynthesis of starch and zeins, we discovered novel target genes of ZmNAC128/130 involved in the biosynthesis of lipids and indole‐3‐acetic acid (IAA). Consistently, the number of oil bodies, as well as the contents of triacylglycerol, and IAA were significantly reduced in zmnac128/130. The hierarchical regulatory network centered by ZmNAC128/130 revealed a significant overlap between the direct target genes of ZmNAC128/130 and their downstream TFs, particularly in regulating the biosynthesis of storage reserves and IAA.Our results indicated that the biosynthesis of storage reserves and IAA is coordinated by a multi‐TFs hierarchical regulatory network in maize endosperm. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results