期刊文献+
共找到11篇文章
< 1 >
每页显示 20 50 100
Squamous cell carcinoma associated with endometriosis in the uterus and ovaries:A case report
1
作者 Zhe Cai Gao-Liang Yang +4 位作者 Qing Li lei zeng Li-Xiang Li Yi-Pei Song Fan-Rong Liu 《World Journal of Clinical Cases》 SCIE 2023年第26期6240-6245,共6页
BACKGROUND Endometriosis is a common benign gynecological disease that causes dysmenorrhea in women of childbearing age.Malignant tumors derived from endometriosis are rarely reported and are found in only 1%of all pa... BACKGROUND Endometriosis is a common benign gynecological disease that causes dysmenorrhea in women of childbearing age.Malignant tumors derived from endometriosis are rarely reported and are found in only 1%of all patients with endometriosis.Here,we report a well-differentiated squamous cell carcinoma(SCC)caused by squamous metaplasia of endometriosis that co-occurred in the uterus and ovaries.CASE SUMMARY A 57-year-old postmenopausal woman had a 6-month history of irregular uterine bleeding.The uterus and adnexa were examined by computed tomography,and there were two solid cystic masses in the pelvis and right adnexa.Histological findings of surgical specimens showed well-differentiated SCC arising from squamous metaplasia of ectopic endometrial glands in the uterus and ovaries.The patient received chemotherapy after surgery and was followed up for 3 mo without metastasis.CONCLUSION The continuity between ectopic endometrial glands and SCC supports that SCC originates from ectopic endometrial glands with metaplasia towards squamous epithelium. 展开更多
关键词 Squamous cell carcinoma OVARIES UTERUS ENDOMETRIOSIS Case report
下载PDF
Expression of serine protease SNC19/matriptase and its inhibitor hepatocyte growth factor activator inhibitor type 1 in normal and malignant tissues of gastrointestinal tract 被引量:9
2
作者 lei zeng Jiang Cao Xing Zhang 《World Journal of Gastroenterology》 SCIE CAS CSCD 2005年第39期6202-6207,共6页
AIM: To provide the expression profile of serine protease SNC19/matriptase and its inhibitor hepatocyte growth factor activator inhibitor type 1 (HAI-1) in normal and malignant tissues of gastrointestinal tract at ... AIM: To provide the expression profile of serine protease SNC19/matriptase and its inhibitor hepatocyte growth factor activator inhibitor type 1 (HAI-1) in normal and malignant tissues of gastrointestinal tract at mRNA level for further study on their correlations with tumor progression and metastasis. METHODS: Total RNAs were prepared from 37 samples of colorectal cancer tissues, 40 samples of gastric cancer tissues, and their adjacent normal tissues. The expression of SNC19/matriptase and HAI-1 in these samples was detected by real-time fluorescent quantitative PCR using glyceraldehyde-3-phosphate dehydrogenase as internal standard, and the clinical significance for the correlation with clinicopathological parameters was evaluated. RESULTS: In gastric cancer tissues the expression of HAI-1 and SNC19/matriptase was significantly lower than that in the corresponding adjacent normal tissues (Z = -3.280, P= 0.006; Z= -4.651, P= 0.000). HAI-1:SNC19/matriptase ratio showed no difference between normal and malignant tissues (P〉0.05). Analysis of clinicopathological parameters showed decreased expression of HAI-1 and HAI-1:SNC19/ matriptase ratio associated with stage Ⅲ/Ⅳ gastric tumors as compared to stage Ⅰ/Ⅱ ones (Z= -2.140, P= 0.031; Z = -2.155, P = 0.031), and with lymph node-positive gastric cancer tissues as compared to lymph node-negative ones (Z = -2.081, P = 0.036; Z= -2.686, P = 0.006). The expression of SNC19/matriptase had no relationship with stages and lymph node metastasis (P〉0.05). The expression of HAI-1 and HAI-1:SNC19/matriptase ratio increased in well-differentiated gastric cancer tissues, but there was no statistical significance (P〉0.05). The difference of SNC19/matriptase expression was not significant in gastric cancer tissues of different histological differentiation status (P〉0.05). In colorectal cancer tissues, the expression of HAI-1 and SNC19/matriptase was also markedly lower than that in their adjacent normal tissues (Z= -3.100, P = 0.002; Z= -2.731, P = 0.006), whereas HAI-1:SNC19/matriptase ratio showed no difference. Decreased expression of HAI-1 was associated with increased invasive depth and lymph node metastasis, but there was no statistical significance (P〉0.05). The difference of SNC19/matriptase expression and HAI-1: SNC19/matriptase ratio was not significant in different stages and different lymph node metastasis status (P〉0.05). The expression of SNC19/matriptase, HAI-1 or HAI-1: SNC19/matriptase ratio showed no difference in colorectal cancer tissues of different histological differentiation status (P〉0.05). CONCLUSION: The expressions of SNC19/matriptase and its inhibitor HAI-1 are decreased in gastrointestinal cancer tissues compared to their normal counterparts, and the decreased expression of HAI-1 may correlate with invasion and lymph node metastasis. The possible mechanisms involved need to be further investigated. 展开更多
关键词 MATRIPTASE Hepatocyte growth factor activator inhibitor type 1 EXPRESSION Metastasis
下载PDF
Probabilistic Lane-Change Decision-Making and Planning for Autonomous Heavy Vehicles 被引量:4
3
作者 Wen Hu Zejian Deng +4 位作者 Dongpu Cao Bangji Zhang Amir Khajepour lei zeng Yang Wu 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2022年第12期2161-2173,共13页
To improve the safety and driving stability of the autonomous heavy truck, it is necessary to consider the differences of driving behavior and drivable trajectories between the heavy trucks and passenger cars. This st... To improve the safety and driving stability of the autonomous heavy truck, it is necessary to consider the differences of driving behavior and drivable trajectories between the heavy trucks and passenger cars. This study proposes a probabilistic decision-making and trajectory planning framework for the autonomous heavy trucks. Firstly, the driving decision process is divided into intention generation and feasibility evaluations, which are realized using the utility theory and risk assessment, respectively. Subsequently the driving decision is made and sent to the trajectory planning module. In order to reflect the greater risks of the truck to other surrounding vehicles, the aggressiveness index(AI) is proposed and quantified to infer the asymmetrical risk level of lane-change maneuver. In the planning stage, the lateral and roll dynamics stability domains are developed as the constraints to exclude the candidate trajectories that would cause vehicle instability. Finally, the simulation results are compared between the proposed model and the artificial potential filed model in the scenarios extracted from the naturalistic driving data. It is shown that the proposed framework can provide the human-like lane-change decisions and truck-friendly trajectories, and performs well in dynamic driving environments. 展开更多
关键词 Autonomous heavy truck DECISION-MAKING driving aggressiveness risk assessment trajectory planning
下载PDF
Effects of groundwater level on vegetation in the arid area of western China 被引量:8
4
作者 Ge Song Jin-ting Huang +2 位作者 Bo-han Ning Jia-wei Wang lei zeng 《China Geology》 2021年第3期527-535,共9页
At present,investigation about the relationship between the change of groundwater level and vegetation mostly focuses on specific watersheds,i.e.limited in river catchment scale.Understanding the change of groundwater... At present,investigation about the relationship between the change of groundwater level and vegetation mostly focuses on specific watersheds,i.e.limited in river catchment scale.Understanding the change of groundwater level on vegetation in the basin or large scale,be urgently needed.To fill this gap,two typical arid areas in the west of China(Tarim Basin and Qaidam Basin)were chosen the a typical research area.The vegetation status was evaluated via normalization difference vegetation index(NDVI)from 2000 to 2016,sourced from MODN1F dataset.The data used to reflect climate change were download from CMDSC(http://data.cma.cn).Groundwater level data was collected from monitor wells.Then,the relationship of vegetation and climate change was established with univariate linear regression and correlation analysis approach.Results show that:Generally,NDVI value in the study area decreased before 2004 then increased in the research period.Severe degradation was observed in the center of the basin.The area with an NDVI value>0.5 decreased from 12%to 6%between 2000 and 2004.From 2004 to 2014,the vegetation in the study area was gradually restored.The whole coverage of Qaidam Basin was low.And the NDVI around East Taigener salt-lake degraded significantly,from 0.596 to 0.005,2014 and 2016,respectively.The fluctuation of groundwater level is the main reason for the change of surface vegetation coverage during the vegetation degradation in the basin.However,the average annual precipitation in the study area is low,which is not enough to have a significant impact on vegetation growth.The annual average precipitation showed an increase trend during the vegetation restoration in the basin,which alleviates the water shortage of vegetation growth in the region.Meanwhile,the dependence of surface vegetation on groundwater is obviously weakened with the correlation index is−0.248.The research results are of some significance to eco-environment protection in the arid area of western China. 展开更多
关键词 NDVI Groundwater level Climate change Arid land Hydrogeological survey engineering Tarim Basin Qaidam Basin Western China
下载PDF
Improved Double Deep Q Network-Based Task Scheduling Algorithm in Edge Computing for Makespan Optimization
5
作者 lei zeng Qi Liu +1 位作者 Shigen Shen Xiaodong Liu 《Tsinghua Science and Technology》 SCIE EI CAS CSCD 2024年第3期806-817,共12页
Edge computing nodes undertake an increasing number of tasks with the rise of business density.Therefore,how to efficiently allocate large-scale and dynamic workloads to edge computing resources has become a critical ... Edge computing nodes undertake an increasing number of tasks with the rise of business density.Therefore,how to efficiently allocate large-scale and dynamic workloads to edge computing resources has become a critical challenge.This study proposes an edge task scheduling approach based on an improved Double Deep Q Network(DQN),which is adopted to separate the calculations of target Q values and the selection of the action in two networks.A new reward function is designed,and a control unit is added to the experience replay unit of the agent.The management of experience data are also modified to fully utilize its value and improve learning efficiency.Reinforcement learning agents usually learn from an ignorant state,which is inefficient.As such,this study proposes a novel particle swarm optimization algorithm with an improved fitness function,which can generate optimal solutions for task scheduling.These optimized solutions are provided for the agent to pre-train network parameters to obtain a better cognition level.The proposed algorithm is compared with six other methods in simulation experiments.Results show that the proposed algorithm outperforms other benchmark methods regarding makespan. 展开更多
关键词 edge computing task scheduling reinforcement learning MAKESPAN Double Deep Q Network(DQN)
原文传递
A facile method to introduce a donor-acceptor system into polymeric carbon nitride for efficient photocatalytic overall water splitting 被引量:1
6
作者 Yabin Jiang Chi Cao +5 位作者 Yueyang Tan Qianwen Chen lei zeng Wensheng Yang Zongzhao Sun Limin Huang 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2023年第10期32-41,共10页
It is a prospective strategy to produce sustainable energy by photocatalytic overall water splitting(POWS).This work aims to develop a simple method for integrating a donor-acceptor system into polymeric car-bon nitri... It is a prospective strategy to produce sustainable energy by photocatalytic overall water splitting(POWS).This work aims to develop a simple method for integrating a donor-acceptor system into polymeric car-bon nitride(PCN)structure,which could accelerate the charge separation significantly.In the as-prepared photocatalyst(COCNT),carbon and oxygen were successfully incorporated into the framework of PCN,and the chemical environment of C and O was well probed by X-ray absorption near-edge structure(XANES)and X-ray photoelectron spectroscopy(XPS).It showed that the C-containing and O-containing segments of COCNT played the role of a donor,while the heptazine part played the role of an acceptor.In addition,Density-functional-theory(DFT)calculations confirmed the spatial split of the highest occupied molec-ular orbital(HOMO)and lowest unoccupied molecular orbital(LUMO)for promoting charge separation.Impressively,COCNT could efficiently split pure water to generate hydrogen and oxygen.And,the photo-catalytic hydrogen evolution rate over COCNT(1550.9μmol g^(-1)h^(-1))is about 17-fold higher than that of PCN.Finally,we proposed a possible photocatalytic mechanism to explain the above results. 展开更多
关键词 Polymeric carbon nitride Donor-accept system Tubular structure PHOTOCATALYSIS Overall water splitting
原文传递
High-dimensional frequency conversion in a hot atomic system
7
作者 张伟航 叶英豪 +4 位作者 曾雷 李恩泽 彭景元 丁冬生 史保森 《Chinese Optics Letters》 SCIE EI CAS CSCD 2023年第9期113-117,共5页
One of the major difficulties in realizing a high-dimensional frequency converter for conventional optical vortex(COV)modes stems from the difference in ring diameter of the COV modes with different topological charge... One of the major difficulties in realizing a high-dimensional frequency converter for conventional optical vortex(COV)modes stems from the difference in ring diameter of the COV modes with different topological charge numbers l.Here,we implement a high-dimensional frequency converter for perfect optical vortex(POV)modes with invariant sizes by way of the four-wave mixing(FWM)process using Bessel–Gaussian beams instead of Laguerre–Gaussian beams.The measured conversion efficiency from 1530 to 795 nm is independent of l at least in subspace l∈{-6,………,6},and the achieved conversion fidelities for two-dimensional(2D)superposed POV states exceed 97%.We further realize the frequency conversion of 3D,5D,and 7D superposition states with fidelities as high as 96.70%,89.16%,and 88.68%,respectively.The proposed scheme is implemented in hot atomic vapor.It is also compatible with the cold atomic system and may find applications in high-capacity and long-distance quantum communication. 展开更多
关键词 high dimension frequency conversion four-wave mixing perfect optical vortex
原文传递
Design and implementation of feedback logic of FOFB for HEPS
8
作者 Daoyuan Wang Dapeng Jin +4 位作者 Peng Zhu Zhexin Xie lei zeng Yuliang Zhang Yongcheng He 《Radiation Detection Technology and Methods》 CSCD 2023年第3期372-381,共10页
Purpose As a fourth-generation light source,High Energy Photon Source(HEPS)has much more stringent requirements to the beam orbit stability in both horizontal and vertical directions than the previous sources due to t... Purpose As a fourth-generation light source,High Energy Photon Source(HEPS)has much more stringent requirements to the beam orbit stability in both horizontal and vertical directions than the previous sources due to the much smaller beam sizes.Methods A Fast Orbit FeedBack(FOFB)system,with the closed-loop bandwidth around 500 Hz,is needed to meet the critical requirements.The latency of the FOFB system is the key to achieve these requirements.Results Proper design and implementation of the feedback logic to have low latency is illustrated in the paper.Calculation accuracy is kept in the whole operation except for the last-minute data translation into 32-bit floating point number. 展开更多
关键词 HEPS Fast orbit feedback system FPGA LATENCY PIPELINE
原文传递
Single metal atom decorated photocatalysts:Progress and challenges 被引量:8
9
作者 lei zeng Can Xue 《Nano Research》 SCIE EI CAS CSCD 2021年第4期934-944,共11页
Photocatalysis has attracted intense attention due to its potential to solve the energy resource problem and environmental issues.The single metal atom decorated photocatalysts as a rising star become more and more po... Photocatalysis has attracted intense attention due to its potential to solve the energy resource problem and environmental issues.The single metal atom decorated photocatalysts as a rising star become more and more popular because of the unique advantages of superior catalytic activities and ultrahigh atom utilization efficiency.The key function of single metal atom catalysts in photocatalytic reactions is boosting surface redox reactions by utilizing photogenerated charges,and has been verified by various spectroscopic and microscopic techniques.Nevertheless,the activities of the single metal atoms highly depend on the binding environment in the host photocatalyst that affect the adsorption and activation of reactants as well as the reaction energy barrier.Herein,this mini review summarizes recent progress on single metal atom decorated photocatalysts,and discusses the roles of the single metal atom catalysts in different types of host photocatalysts including organic,carbon-based and inorganic materials.The remaining challenges and future perspectives on the stability and activities of single atom catalysts in photocatalytic processes are elaborated in the end.We believe that this mini review will provide valuable overview on synthetic methods of different single atom photocatalysts for researchers towards future development of highly efficient photocatalysts. 展开更多
关键词 PHOTOCATALYSIS solar fuels hydrogen generation CO_(2)reduction artificial photosynthesis solar energy conversion
原文传递
Preparation and characterization of bioactive glass tablets and evaluation of bioactivity and cytotoxicity in vitro 被引量:1
10
作者 Jianhui Chen lei zeng +2 位作者 Xiaofeng Chen Tianshun Liao Jiafu Zheng 《Bioactive Materials》 SCIE 2018年第3期315-321,共7页
In this study, the SiO2eCaOeP2O5 ternary component of bioactive glass particles were successfullysynthesized by sol-gel method, then the bioactive glass particles were pressed into tablets with drypressing molding tec... In this study, the SiO2eCaOeP2O5 ternary component of bioactive glass particles were successfullysynthesized by sol-gel method, then the bioactive glass particles were pressed into tablets with drypressing molding technology. The physicochemical structure, in-vitro bioactivity and biocompatibility ofBG tablets were characterized by various methods, such as XRD、SEM、FTIR, etc. The results showedthat the sol-gel bioactive glass particle was distinguished with its amorphous structure and micron-size.After being soaked in Tris-Hcl solution for 15 d, the bioactive glass tablets didn't collapse. Also, themineralization assay in vitro showed that the bioactive glass tablets had good capability of inducing theformation of hydroxycarbonate apatite (HCA) after being immersed in simulated body fluid (SBF). Inaddition, the cytotoxicity assay indicated that the osteoblast (MC3T3) grew well on the surface ofbioactive glass tablets. According to the above results, the bioactive glass tablets presented good mechanicalstrength, excellent apatite-forming activity and high biocompatibility, which demonstratedtheir potential applications in the field of bone defect repairing. 展开更多
关键词 Sol-gel bioactive glass Dry pressing molding BG tablets Bioactivity CYTOTOXICITY
原文传递
Accumulation of localized charge on the surface of polymeric carbon nitride boosts the photocatalytic activity
11
作者 Yabin Jiang lei zeng +2 位作者 Chi Cao Wensheng Yang Limin Huang 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2022年第16期9-16,共8页
The random mobility of charge carriers is a main factor causing the low photocatalytic efficiency of gCN.Thus,the controllable migration of charge carriers is a rational strategy to suppress the charge recombination a... The random mobility of charge carriers is a main factor causing the low photocatalytic efficiency of gCN.Thus,the controllable migration of charge carriers is a rational strategy to suppress the charge recombination and facilitate charge separation.Herein,an ethylenediamine modified g-C_(3)N_(4)displays improved photocatalytic activity.The excellent charge separation efficiency is confirmed to be a key factor for the enhancement.The TEM observation after photo-depositing Pt nanoparticles and DFT calculations verify the accumulation of electrons on some areas of g-C_(3)N_(4)surface.The increased-NH_(2)groups significantly tune the electronic structure of g-C_(3)N_(4)after the modification.The generation of midgap states also affects the charge separation.Our reports provide a simple method to manage the migration of charge carriers and enable electrons directional transfer,which suppresses the recombination and improves the photocatalytic activity. 展开更多
关键词 g-C_(3)N_(4) Charge separation Photocatalytic H2 evolution Directional migration
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部