期刊文献+
共找到116篇文章
< 1 2 6 >
每页显示 20 50 100
The testis-specific gene 1700030J22Rik is essential for sperm flagellar function and male fertility in mice
1
作者 Damin Yun Sheng Gao +7 位作者 Xinyao Li Jie Shi Lingling Wang Tiao Bu Xiwen Yang Yunhao Wu Xiaolong Wu fei sun 《Journal of Genetics and Genomics》 2025年第7期927-941,共15页
Spermiogenesis is an indispensable process occurring during the later stages of spermatogenesis.Despite multiple proteins being associated with spermiogenesis,the molecular mechanisms that control spermiogenesis remai... Spermiogenesis is an indispensable process occurring during the later stages of spermatogenesis.Despite multiple proteins being associated with spermiogenesis,the molecular mechanisms that control spermiogenesis remain poorly characterized.In this study,we show that 1700030J22Rik is exclusively expressed in testes of mice and investigate its roles in spermiogenesis using genetic and proteomic approaches.The deficiency in 1700030J22Rik in male mice results in severe subfertility,characterized by a substantial decrease in sperm concentration,motility,and abnormalities in the flagella.Furthermore,1700030J22RIK interacts with the A-kinase-anchoring protein AKAP3,and 1700030J22Rik knockout decreases AKAP3 and AKAP4 protein levels.Additionally,the absence of 1700030J22RIK alters spermatozoal levels of the subunits of protein kinase A,leading to reduced protein phosphorylation and impaired sperm motility.This study reveals that 1700030J22Rik plays a crucial role in the organization of sperm morphology and function in mice. 展开更多
关键词 Male infertility SPERMIOGENESIS Asthenoteratozoospermia FLAGELLUM 1700030J22RIK Protein kinase A
原文传递
A review on multi-scale structure engineering of carbon-based electrode materials towards dense energy storage for supercapacitors
2
作者 Dongyang Wu fei sun +5 位作者 Min Xie Hua Wang Wei Fan Jihui Gao Guangbo Zhao Shaoqin Liu 《Journal of Energy Chemistry》 2025年第3期768-799,共32页
Improving the volumetric energy density of supercapacitors is essential for practical applications,which highly relies on the dense storage of ions in carbon-based electrodes.The functional units of carbon-based elect... Improving the volumetric energy density of supercapacitors is essential for practical applications,which highly relies on the dense storage of ions in carbon-based electrodes.The functional units of carbon-based electrode exhibit multi-scale structural characteristics including macroscopic electrode morphologies,mesoscopic microcrystals and pores,and microscopic defects and dopants in the carbon basal plane.Therefore,the ordered combination of multi-scale structures of carbon electrode is crucial for achieving dense energy storage and high volumetric performance by leveraging the functions of various scale structu re.Considering that previous reviews have focused more on the discussion of specific scale structu re of carbon electrodes,this review takes a multi-scale perspective in which recent progresses regarding the structureperformance relationship,underlying mechanism and directional design of carbon-based multi-scale structures including carbon morphology,pore structure,carbon basal plane micro-environment and electrode technology on dense energy storage and volumetric property of supercapacitors are systematically discussed.We analyzed in detail the effects of the morphology,pore,and micro-environment of carbon electrode materials on ion dense storage,summarized the specific effects of different scale structures on volumetric property and recent research progress,and proposed the mutual influence and trade-off relationship between various scale structures.In addition,the challenges and outlooks for improving the dense storage and volumetric performance of carbon-based supercapacitors are analyzed,which can provide feasible technical reference and guidance for the design and manufacture of dense carbon-based electrode materials. 展开更多
关键词 SUPERCAPACITORS Carbon-based electrodes Volumetric performances Multi-scale structure Dense energy storage
在线阅读 下载PDF
BIM-based Construction Collision Detection and Pipeline Comprehensive Optimization
3
作者 fei sun 《Journal of World Architecture》 2025年第4期66-72,共7页
This paper explores the application of Building Information Modeling(BIM)technology in pipeline collision detection and optimization for a station and operation section project of Line 2 in a specific city.By leveragi... This paper explores the application of Building Information Modeling(BIM)technology in pipeline collision detection and optimization for a station and operation section project of Line 2 in a specific city.By leveraging BIM for 3D modeling,the study facilitates the identification of pipeline conflicts,enabling comprehensive optimization of the pipeline layout.Navisworks software is used for visualizing the model,providing an intuitive platform for detecting clashes and refining the pipeline design.The proposed BIM-based approach not only enhances construction efficiency by reducing rework and conflicts but also improves project quality through more accurate,coordinated designs.While the focus is on the construction industry,the methods discussed are applicable to various fields,offering broader potential for improving integration and efficiency in other types of construction projects. 展开更多
关键词 BIM Collision detection Pipeline optimization
在线阅读 下载PDF
Integrating Iron Overload Diagnosis with Electrocardiographic Abnormalities:Bridging Laboratory Findings to Primary Care Practice
4
作者 Xinqi Liu Xinhan Liu +2 位作者 Roohollah Changizi fei sun Xinlian Jin 《Proceedings of Anticancer Research》 2025年第5期65-73,共9页
Objective:To investigate the diagnostic status and electrocardiographic correlates in patients with biochemical evidence of iron overload.Methods:We conducted a retrospective cohort study of patients in our hospital w... Objective:To investigate the diagnostic status and electrocardiographic correlates in patients with biochemical evidence of iron overload.Methods:We conducted a retrospective cohort study of patients in our hospital with ferritin levels exceeding 500 ng/mL between January 1,2011,and October 24,2022(corresponding to the pre-COVID-19 pandemic period in Beijing).Using ICD-10-CM coded medical records,we assessed the following:definitive diagnostic characterization(genetic or acquired),electrocardiographic(ECG)completion rates,and the prevalence of ECG abnormalities.Statistical analyses,encompassing chi-square tests and correlation studies,were performed using SPSS Statistics software(version 27.0).Results:Except for cases of malignancy,infectious diseases,hematological diseases,chronic diseases,for the unexplained diagnosis group found elevated ferritin during annual health checkup,there were 17 cases in the group with ferritin above 1,000 ng/ml and 36 cases in the group with ferritin ranging from 500 to 1,000 ng/ml,accounting for 23.2%and 25.8%of the entire ferritin analysis respectively,and the total proportion in the entire analysis was 24.0%.Among the cases indicating ferritin higher than 500ng/ml,24.0%of the cases were of unknown diagnosis.ECG acquisition rate for was 55.7%,with 24% demonstrating abnormalities,including atrial fibrillation,sinus tachycardia arrhythmia,atrioventricular block,prolonged QT interval,T-wave inversion,and ST-segment depression.Conclusion:The study revealed that the proportion of unexplained diagnoses of ferritin overload remains relatively high,and the analysis of the ECG is also insufficient.There is a need to enhance clinicians’awareness and attention to iron overload in both diagnosis and ECG analysis. 展开更多
关键词 FERRITIN ELECTROCARDIOGRAM ECG
暂未订购
Simultaneously realizing thermal and electromagnetic cloaking by multi-physical null medium 被引量:1
5
作者 Yichao Liu Xiaomin Ma +6 位作者 Kun Chao fei sun Zihao Chen Jinyuan Shan Hanchuan Chen Gang Zhao Shaojie Chen 《Opto-Electronic Science》 2024年第2期45-59,共15页
Simultaneously manipulating multiple physical fields plays an important role in the increasingly complex integrated systems,aerospace equipment,biochemical productions,etc.For on-chip systems with high integration lev... Simultaneously manipulating multiple physical fields plays an important role in the increasingly complex integrated systems,aerospace equipment,biochemical productions,etc.For on-chip systems with high integration level,the precise and efficient control of the propagation of electromagnetic waves and heat fluxes simultaneously is particularly important.In this study,we propose a graphical designing method(i.e.,thermal-electromagnetic surface transformation)based on thermal-electromagnetic null medium to simultaneously control the propagation of electromagnetic waves and thermal fields according to the pre-designed paths.A thermal-electromagnetic cloak,which can create a cloaking effect on both electromagnetic waves and thermal fields simultaneously,is designed by thermal-electromagnetic surface transformation and verified by both numerical simulations and experimental measurements.The thermal-electromagnetic surface transformation proposed in this study provides a new methodology for simultaneous controlling on electromagnetic and temperature fields,and may have significant applications in improving thermal-electromagnetic compatibility problem,protecting of thermal-electromagnetic sensitive components,and improving efficiency of energy usage for complex onchip systems. 展开更多
关键词 transformation optics multi-physical cloak null medium
在线阅读 下载PDF
Meiotic transcriptional reprogramming mediated by cell-cell communications in humans and mice revealed by scATACseq and scRNA-seq
6
作者 Hai-Quan Wang Xiao-Long Wu +6 位作者 Jing Zhang Si-Ting Wang Yong-Juan Sang Kang Li Chao-Fan Yang fei sun Chao-Jun Li 《Zoological Research》 SCIE CSCD 2024年第3期601-616,共16页
Meiosis is a highly complex process significantly influenced by transcriptional regulation.However,studies on the mechanisms that govern transcriptomic changes during meiosis,especially in prophase I,are limited.Here,... Meiosis is a highly complex process significantly influenced by transcriptional regulation.However,studies on the mechanisms that govern transcriptomic changes during meiosis,especially in prophase I,are limited.Here,we performed single-cell ATAC-seq of human testis tissues and observed reprogramming during the transition from zygotene to pachytene spermatocytes.This event,conserved in mice,involved the deactivation of genes associated with meiosis after reprogramming and the activation of those related to spermatogenesis before their functional onset.Furthermore,we identified 282 transcriptional regulators(TRs)that underwent activation or deactivation subsequent to this process.Evidence suggested that physical contact signals from Sertoli cells may regulate these TRs in spermatocytes,while secreted ENHO signals may alter metabolic patterns in these cells.Our results further indicated that defective transcriptional reprogramming may be associated with non-obstructive azoospermia(NOA).This study revealed the importance of both physical contact and secreted signals between Sertoli cells and germ cells in meiotic progression. 展开更多
关键词 Single-cell RNA-seq Single-cell ATAC-seq SPERMATOGENESIS MEIOSIS Transcriptional reprogramming Cell-cell communication
在线阅读 下载PDF
预测典型变形高温合金均匀化动力学的新模型
7
作者 张献光 杨文超 +9 位作者 周扬 闫建昊 肖东平 税烺 付建辉 孙飞 石鹏 陈佳俊 裴逸武 张健 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2024年第4期1178-1190,共13页
提出一种基于扩散距离概念的变形高温合金均匀化动力学新预测模型。通过定量电子探针(EPMA)分析,系统研究典型镍基变形高温合金(GH4141)的微观偏析和均匀化动力学。研究发现,基于残余偏析指数模型预测的均匀化动力学与实际测量结果之间... 提出一种基于扩散距离概念的变形高温合金均匀化动力学新预测模型。通过定量电子探针(EPMA)分析,系统研究典型镍基变形高温合金(GH4141)的微观偏析和均匀化动力学。研究发现,基于残余偏析指数模型预测的均匀化动力学与实际测量结果之间存在一定差异。实验和理论分析均表明,考虑了过去通常被忽略的扩散方向因子的一维扩散距离模型可以合理地预测均化动力学。新模型在只需知道原始枝晶臂间距和扩散系数前提下即可完成预测计算,这为变形高温合金均匀化动力学预测提供了一种新的选择。 展开更多
关键词 变形高温合金 微观偏析 均匀化动力学 预测模型 扩散距离
在线阅读 下载PDF
A natural compound-empowered podophyllotoxin prodrug nanoassembly magnifies efficacy-toxicity benefits in cancer chemotherapy
8
作者 Ziqi Lin Yuequan Wang +6 位作者 Wenwen Li fei sun Qingzhi Lv Shenwu Zhang Xiaohong Liu Feng Qin Cong Luo 《Asian Journal of Pharmaceutical Sciences》 SCIE CAS 2024年第4期103-114,共12页
Small-molecule prodrug nanoassembly technology with a unique advantage in off-target toxicity reduction has been widely used for antitumor drug delivery.However,prodrug activation remains a rate-limiting step for exer... Small-molecule prodrug nanoassembly technology with a unique advantage in off-target toxicity reduction has been widely used for antitumor drug delivery.However,prodrug activation remains a rate-limiting step for exerting therapeutic actions,which requires to quickly reach the minimum valid concentrations of free drugs.Fortunately,we find that a natural compound(BL-193)selectively improves the chemotherapy sensitivity of breast cancer cells to podophyllotoxin(PPT)at ineffective dose concentrations.Based on this,we propose to combine prodrug nanoassembly with chemotherapy sensitization to fully unleash the chemotherapeutic potential of PPT.Specifically,a redox-sensitive prodrug(PSSF)of PPT is synthesized by coupling 9-fluorenyl-methanol(Fmoc-OH)with PPT linked via disulfide bond.Intriguingly,PSSF with aπ-conjugated structure readily co-assembles with BL-193 into stable nanoassembly.Significantly,BL-193 serves as an excellent chemosensitizer that creates an ultra-low-dose chemotherapeutic windowfor PPT.Moreover,prodrug design and precise hybrid nanoassembly well manage off-target toxicity.As expected,such a BL-193-empowered prodrug nanoassembly elicits potent antitumor responses.This study offers a novel paradigm to magnify chemotherapy efficacy-toxicity benefits. 展开更多
关键词 Podophyllotoxin PRODRUG CHEMOSENSITIZATION Hybrid nanoassembly Cancer chemotherapy
暂未订购
Anomalous bond lengthening in compressed magnetic doped semiconductor Ba(Zn_(0.95)Mn_(0.05))_(2)As_(2)
9
作者 fei sun Yi Peng +3 位作者 Guoqiang Zhao Xiancheng Wang Zheng Deng Changqing Jin 《Journal of Semiconductors》 EI CAS CSCD 2024年第4期36-41,共6页
Applying pressure has been evidenced as an effective method to control the properties of semiconductors,owing to its capability to modify the band configuration around Fermi energy.Correspondingly,structural evolution... Applying pressure has been evidenced as an effective method to control the properties of semiconductors,owing to its capability to modify the band configuration around Fermi energy.Correspondingly,structural evolutions under external pres-sures are required to analyze the mechanisms.Herein high-pressure structure of a magnetic doped semiconductor Ba(Zn_(0.95)Mn_(0.05))_(2)As_(2)is studied with combination of in-situ synchrotron X-ray diffractions and diamond anvil cells.The materials become ferromagnetic with Curie temperature of 105 K after further 20%K doping.The title material undergoes an isostruc-tural phase transition at around 19 GPa.Below the transition pressure,it is remarkable to find lengthening of Zn/Mn-As bond within Zn/MnAs layers,since chemical bonds are generally shortened with applying pressures.Accompanied with the bond stretch,interlayer As-As distances become shorter and the As-As dimers form after the phase transition.With further compres-sion,Zn/Mn-As bond becomes shortened due to the recovery of isotropic compression on the Zn/MnAs layers. 展开更多
关键词 magnetic semiconductor high-pressure in-situ X-ray diffraction phase transition
在线阅读 下载PDF
Photodoping-Modified Charge Density Wave Phase Transition in WS_(2)/1T-TaS_(2) Heterostructure
10
作者 王瑞 丁建伟 +2 位作者 孙飞 赵继民 裘晓辉 《Chinese Physics Letters》 SCIE EI CAS CSCD 2024年第5期144-170,共27页
Controlling collective electronic states hold great promise for development of innovative devices. Here, we experimentally detect the modification of the charge density wave(CDW) phase transition within a 1T-TaS_(2) l... Controlling collective electronic states hold great promise for development of innovative devices. Here, we experimentally detect the modification of the charge density wave(CDW) phase transition within a 1T-TaS_(2) layer in a WS_(2)/1T-TaS_(2) heterostructure using time-resolved ultrafast spectroscopy. Laser-induced charge transfer doping strongly suppresses the commensurate CDW phase, which results in a significant decrease in both the phase transition temperature(T_(c)) and phase transition stiffness. We interpret the phenomenon that photoinduced hole doping, when surpassing a critical threshold value of ~ 10^(18)cm^(-3), sharply decreases the phase transition energy barrier. Our results provide new insights into controlling the CDW phase transition, paving the way for optical-controlled novel devices based on CDW materials. 展开更多
关键词 DOPING TRANSITION TRANSITION
原文传递
冷冻聚焦离子束-扫描电镜成像技术研究进展 被引量:3
11
作者 贾星 孙飞 季刚 《植物学报》 CAS CSCD 北大核心 2022年第1期24-29,共6页
冷冻聚焦离子束-扫描电镜成像(Cryo-FIB-SEM)是一种新兴的成像检测技术,在原位进行冷冻聚焦离子束切割和冷冻扫描电镜成像,为研究天然含水状态下生物样品内部未被破坏的原始结构打开了一扇窗口。近年来,该技术在生命科学领域的应用研究... 冷冻聚焦离子束-扫描电镜成像(Cryo-FIB-SEM)是一种新兴的成像检测技术,在原位进行冷冻聚焦离子束切割和冷冻扫描电镜成像,为研究天然含水状态下生物样品内部未被破坏的原始结构打开了一扇窗口。近年来,该技术在生命科学领域的应用研究取得了一系列重要进展。该文对其在冷冻体积连续成像、冷冻光电关联成像、冷冻透射扫描成像、冷冻含水切片制备监控及冷冻扫描图像处理等方面的研究进展进行综述,并展望了该技术在大体积生物样品三维原位成像研究领域的前沿性发展趋势,以期推动Cryo-FIB-SEM技术在生物样品三维结构研究中的应用。 展开更多
关键词 冷冻聚焦离子束-扫描电镜成像 冷冻光电关联 冷冻体积连续成像 冷冻透射扫描成像
原文传递
Prevalent false positives of azoospermia factor a (AZFa) microdeletions caused by single-nucleotide polymorphism rs72609647 in the sY84 screening of male infertility 被引量:14
12
作者 Qing Wu Guo-Wu Chen +7 位作者 Tao-fei Yan Hui Wang Yu-Ling Liu Zheng Li Shi-Wei Duan fei sun Yun Feng Hui-Juan Shi 《Asian Journal of Andrology》 SCIE CAS CSCD 2011年第6期877-880,共4页
Multiplex polymerase chain reaction (PCR) has been widely used to detect Y-chromosome micredeletions, which is one of the major causes of male infertility. Both the European Academy of Andrology (EAA) and the Euro... Multiplex polymerase chain reaction (PCR) has been widely used to detect Y-chromosome micredeletions, which is one of the major causes of male infertility. Both the European Academy of Andrology (EAA) and the European Molecular Genetics Quality Network (EMQN) have recommended the use of sY84 and sY86 markers for the detection of azoospermia factor a (AZFa) microdeletion during DNA testing for male infertility. In this study, a large-scale analysis of AZF microdeletion in a total of 630 Chinese males, including healthy semen donors (n=200), infertile males with normal sperm count (n=226) and patients with either nonobstructive azoospermia or severe oligozoospermia (n=204), was performed. A series of nine sequence-tagged site (STS) markers from the AZF region of the Y chromosome was used to detect microdeletions. All primers were designed based on the recommendations of the National Center for Biotechnology Information. An unusually high incidence (73/630, 11.6%) of sY84-absent but sY86-present genotypes was observed in the AZFa microdeletion screening. Sequencing the sY84-flanking region revealed a total of 73 patients with sY84-absent but sY86-present genotypes have a T-to-G transversion at the fifth base from the 5' end of the reverse sY84 primer. These prevalent false positives, which were not only observed in infertile men, but also observed in donors, resulted from a single-nucleotide polymorphism (SNP) named rs72609647 in the targeting sequence of the reverse sY84 primer. Our study suggests that a pre-screening of existence of rs72609647 polymorphism can prevent the frequent false positive results of AZFa microdeletions detection in the infertile Chinese males. Given the SNP rs72609647 was recently found in a deep sequencing of a Chinese individual, the current EAA and EMQN standards may need to be scrutinized among different populations to avoid the potential genetic variations in the primer binding sequences. 展开更多
关键词 male infertility multiplex polymerase chain reaction rs72609647 single-nucleotide polymorphism sY84 Y-chromosomemicrodeletion
在线阅读 下载PDF
Rock deformation equations and application to the study on slantingly installed disc cutter 被引量:18
13
作者 Zhao-Huang Zhang Liang Meng fei sun 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2014年第4期540-546,共7页
At present the mechanical model of the interac- tion between a disc cutter and rock mainly concerns indentation experiment, linear cutting experiment and tunnel boring machine (TBM) on-site data. This is not in line... At present the mechanical model of the interac- tion between a disc cutter and rock mainly concerns indentation experiment, linear cutting experiment and tunnel boring machine (TBM) on-site data. This is not in line with the actual rock-breaking movement of the disc cutter and impedes to some extent the research on the rock-breaking mechanism, wear mechanism and design theory. Therefore, our study focuses on the interaction between the slantingly installed disc cutter and rock, developing a model in accordance with the actual rock-breaking movement. Displacement equations are established through an analysis of the velocity vector at the rock-breaking point of the disc cutter blade; the func- tional relationship between the displacement parameters at the rock-breaking point and its rectangular coordinates is established through an analysis of micro-displacement vectors at the rock-breaking point, thus leading to the geometric equations of rock deformation caused by the slantingly installed disc cutter. Considering the basically linear relationship between the cutting force of disc cutters and the rock deformation before and after the leap break of rock, we express the constitutive relations of rock deformation as generalized Hooke's law and analyze the effect of the slanting installa- tion angle of disc cutters on the rock-breaking force. This will, as we hope, make groundbreaking contributions to the development of the design theory and installation practice of TBM. 展开更多
关键词 TBM Disc cutter· Geometric equation Slant-ingly installed Rock-breaking
在线阅读 下载PDF
Fragmentation Energy-Saving Theory of Full Face Rock Tunnel Boring Machine Disc Cutters 被引量:12
14
作者 Zhao-Huang Zhang Guo-Fang Gong +1 位作者 Qing-Feng Gao fei sun 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2017年第4期913-919,共7页
Attempts to minimize energy consumption of a tunnel boring machine disc cutter during the process of fragmentation have largely focused on optimizing disc- cutter spacing, as determined by the minimum specific energy ... Attempts to minimize energy consumption of a tunnel boring machine disc cutter during the process of fragmentation have largely focused on optimizing disc- cutter spacing, as determined by the minimum specific energy required for fragmentation; however, indentation tests showed that rock deforms plastically beneath the cutters. Equations for thrust were developed for both the traditional, popularly employed disc cutter and anew design based on three-dimensional theory. The respective energy consumption for penetration, rolling, and side-slip fragmentations were obtained. A change in disc-cutter fragmentation angles resulted in a change in the nature of the interaction between the cutter and rock, which lowered the specific energy of fragmentation. During actual field excavations to the same penetration length, the combined energy consumption for fragmentation using the newly designed cutters was 15% lower than that when using the traditional design. This paper presents a theory for energy saving in tunnel boring machines. Investigation results showed that the disc cutters designed using this theory were more durable than traditional designs, and effectively lowered the energy consumption. 展开更多
关键词 Newly design Disc cutter FRAGMENTATION Specific energy Energy consumption
在线阅读 下载PDF
APPLICATION OF WHOLE BODY DIFFUSION WEIGHTED MR IMAGING FOR DIAGNOSIS AND STAGING OF MALIGNANT LYMPHOMA 被引量:18
15
作者 Shuo Li Hua-dan Xue +5 位作者 Jian Li fei sun Bo Jiang Dong Liu Hong-yi sun Zheng-yu Jin 《Chinese Medical Sciences Journal》 CAS CSCD 2008年第3期138-144,共7页
Objective To evaluate the clinical impact of whole body diffusion weighted imaging (WB-DWI) on diagnosis and staging of malignant lymphoma. Methods Thirty-one patients with suspected lymphadenopathy were enrolled. ... Objective To evaluate the clinical impact of whole body diffusion weighted imaging (WB-DWI) on diagnosis and staging of malignant lymphoma. Methods Thirty-one patients with suspected lymphadenopathy were enrolled. WB-DWI was performed by using short TI inversion recovery echo-planar imaging sequence with free breathing and built-in body coil. Axial T2- weighted imaging images of the same location were used as reference. The results of WB-DWI were compared with pathological results and other imaging modalities. The mean apparent diffusion coefficient (ADC) values of different kinds of lymph nodes were compared. Results WB-DWI was positive in all 18 cases with lymphoma, 5 cases with metastatic lymph nodes and 4 of 8 eases with benign lymphadenopathy. The mean ADC value of lymphomatous, metastatic and benign lymph nodes was (0.87 ± 0.17) × 10^3, (0.98± 0.09) × 10^3 and (1.20 ± 0.10) × 10^3 mm^2/s. There was significant difference in ADC value between benign lymph nodes and other two groups (P 〈 0.01). The sensitivity, specificity and accuracy of WB-DWI in diagnosis of lymphoma were 100% (18/18), 30.8% (4/13) and 71.0% (22/31). When an ADC value of 1.08 × 10^-3 mm^2/s was used as the threshold value for differentiating malignant from benign lymph nodes, the best results were obtained with sensitivity of 87.8% and specificity of 91.3%. Sixteen of eighteen cases (88.9%) of lymphoma were accurately staged in accordance with clinical staging. Conclusions WB-DWI is a sensitive, but less specific technique for diagnosis of lymphoma. It is difficult to differentiate lymphnmatous from metastatic lymph nodes using WB-DWI. However, it is a valuable imaging modality for staging of patients with malignant lymphoma. 展开更多
关键词 diffusion magnetic resonance imaging whole body imaging short TI inversion recovery LYMPHOMA
暂未订购
CLINICAL APPLICATION OF BODY DIFFUSION WEIGHTED MR IMAGING IN THE DIAGNOSIS AND PREOPERATIVE N STAGING OF CERVICAL CANCER 被引量:28
16
作者 Hua-dan Xue Shuo Li +4 位作者 fei sun Hong-yi sun Zheng-yu Jin Jia-xin Yang Mei Yu 《Chinese Medical Sciences Journal》 CAS CSCD 2008年第3期133-137,共5页
Objective To evaluate the clinical impact of body diffusion weighted imaging (DWI) on the diagnosis and preoperative N staging of cervical cancer. Methods Twenty-four patients (mean age 37.9 years old) with proved cer... Objective To evaluate the clinical impact of body diffusion weighted imaging (DWI) on the diagnosis and preoperative N staging of cervical cancer. Methods Twenty-four patients (mean age 37.9 years old) with proved cervical cancer by cervical biopsy and 24 female patients with other suspected pelvic abnormalities received preoperative body DWI scan. Results of body DWI were compared with pathological findings. The apparent diffusion coefficient (ADC) values of normal cervix and different pathological types of cervical cancer were compared. ADC value of normal or inflammatory lymph nodes was also compared with that of metastatic ones. Student's t test was used for statistical analysis. Results There were 5 adenocarcinomas and 19 epitheliomas showed with biopsy results, and DWI showed 21 cervical lesions out of them (87.5%). ADC values of the normal cervix (n = 24), epithelioma (n = 19), and adenocar- cinoma (n = 5) were (1.73 ± 0.31) ×10-3, (0.88 ± 0.22) ×10-3, and (1.08 ± 0.12) ×10-3 mm2/s, respectively. Statistical analysis showed significant difference in ADC value between normal cervical tissue and either tumor tissues (both P < 0.01). In patients had lymphadenectomy (n = 24), totally 67 lymph nodes including 16 metastatic lymph nodes were pathologically analyzed, and DWI showed 66 (98.5%) out of them. ADC values of normal/inflammatory and metastatic lymph nodes were (1.07 ± 0.16) ×10-3 and (0.77 ± 0.13) ×10-3 mm2/s (P < 0.01). Receiver operating characteristic (ROC) curve of ADC value of metastatic lymph node showed that area under curve was 0.961. Conclusions ADC value in cervical carcinoma is lower than that in normal cervix, and ADC may have predictive value in subtype discrimination. ADC value may improve the preoperative characterization of lymph node metastasis. And at least abdominal and pelvic DWI scan is suggested for N staging evaluation in such patients. 展开更多
关键词 magnetic resonance diffusion weighted imaging cervical cancer
暂未订购
Theoretical prediction of wear of disc cutters in tunnel boring machine and its application 被引量:9
17
作者 Zhaohuang Zhang Muhammad Aqeel +1 位作者 Cong Li fei sun 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2019年第1期111-120,共10页
Predicting the cutter consumption and the exact time to replace the worn-out cutters in tunneling projects constructed with tunnel boring machine(TBM) is always a challenging issue. In this paper, we focus on the anal... Predicting the cutter consumption and the exact time to replace the worn-out cutters in tunneling projects constructed with tunnel boring machine(TBM) is always a challenging issue. In this paper, we focus on the analyses of cutter motion in the rock breaking process and trajectory of rock breaking point on the cutter edge in rocks. The analytical expressions of the length of face along which the breaking point moves and the length of spiral trajectory of the maximum penetration point are derived. Through observation of rock breaking process of disc cutters as well as analysis of disc rock interaction, the following concepts are proposed: the arc length theory of predicting wear extent of inner and center cutters, and the spiral theory of predicting wear extent of gage and transition cutters. Data obtained from5621 m-long Qinling tunnel reveal that among 39 disc cutters, the relative errors between cumulatively predicted and measured wear values for nine cutters are larger than 20%, while approximately 76.9% of total cutters have the relative errors less than 20%. The proposed method could offer a new attempt to predict the disc cutter's wear extent and changing time. 展开更多
关键词 Full-face rock TUNNEL BORING machine(TBM) DISC CUTTER WEAR prediction
在线阅读 下载PDF
FEASIBILITY OF WHOLE BODY DIFFUSION WEIGHTED IMAGING IN DETECTING BONE METASTASIS ON 3.0T MR SCANNER 被引量:12
18
作者 Xian Xu Lin Ma +5 位作者 Jin-shan Zhang You-quan Cai Bai-xuan Xu Liu-quan Chen fei sun Xing-gao Guo 《Chinese Medical Sciences Journal》 CAS CSCD 2008年第3期151-157,共7页
Objective To evaluate the feasibility of whole body diffusion weighted imaging (DWI) in bone metastasis detection using bone scintigraphy as comparison. Methods Forty-five patients with malignancy history were enrolle... Objective To evaluate the feasibility of whole body diffusion weighted imaging (DWI) in bone metastasis detection using bone scintigraphy as comparison. Methods Forty-five patients with malignancy history were enrolled in our study. All the patients received the whole body DWI and bone scintigraphy scan within 1 week. The magnetic resonance (MR) examination was performed on 3.0T MR scanner using embedded body coil. The images were reviewed separately by two radiologists and two nuclear medicine physicians, who were blinded to the results of the other imaging modality. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the two techniques for detecting bone metastasis were analyzed. Results A total of 181 metastatic lesions in 77 regions of 34 patients were detected by whole body DWI, and 167 metastatic lesions in 76 regions of 31 patients were identified by bone scintigraphy. The patient-based sensitivity and PPV of whole body DWI and bone scintigraphy were similar (89.5% vs. 81.6%, 97.1% vs. 91.2%), whereas, the patient-based specificity and NPV of whole body DWI were obviously higher than those of bone scintigraphy (85.7% vs. 57.1%, 60.0% vs. 36.4%). Ten regions negative in scintigraphy but positive in whole body DWI, mainly located in spine, pelvis, and femur; nine regions only detected by scintigraphy, mainly located in skull, sternum, clavicle, and scapula. The region-based sensitivity and specificity of whole body DWI were slightly higher than those of bone scintigraphy (89.5% vs. 88.4%, 95.6% vs. 87.6%). Conclusion Whole body DWI reveals excellent concordance with bone scintigraphy regarding detection of bone metastasis, and the two techniques are complementary for each other. 展开更多
关键词 neoplasm metastasis diffusion weighted imaging bone tissue SCINTIGRAPHY
暂未订购
DOA Estimation Based on Sparse Representation of the Fractional Lower Order Statistics in Impulsive Noise 被引量:10
19
作者 Sen Li Rongxi He +1 位作者 Bin Lin fei sun 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2018年第4期860-868,共9页
This paper is mainly to deal with the problem of direction of arrival(DOA) estimations of multiple narrow-band sources impinging on a uniform linear array under impulsive noise environments. By modeling the impulsive ... This paper is mainly to deal with the problem of direction of arrival(DOA) estimations of multiple narrow-band sources impinging on a uniform linear array under impulsive noise environments. By modeling the impulsive noise as α-stable distribution, new methods which combine the sparse signal representation technique and fractional lower order statistics theory are proposed. In the new algorithms, the fractional lower order statistics vectors of the array output signal are sparsely represented on an overcomplete basis and the DOAs can be effectively estimated by searching the sparsest coefficients. To enhance the robustness performance of the proposed algorithms,the improved algorithms are advanced by eliminating the fractional lower order statistics of the noise from the fractional lower order statistics vector of the array output through a linear transformation. Simulation results have shown the effectiveness of the proposed methods for a wide range of highly impulsive environments. 展开更多
关键词 α-stable distribution direction of arrival(DOA) fractional lower-order statistics impulsive noise sparse representation
在线阅读 下载PDF
MR DIFFUSION WEIGHTED IMAGING FOR EVALUATION OF RADIOTHERAPEUTIC EFFECTS ON RABBIT VX2 TUMOR MODEL 被引量:15
20
作者 Shuo Li Hua-dan Xue +5 位作者 Xin-hai Wang fei sun Bo Jiang Dong Liu Jing Lei Zheng-yu Jin 《Chinese Medical Sciences Journal》 CAS CSCD 2008年第3期172-177,共6页
Objective To investigate the feasibility of magnetic resonance (MR) diffusion weighted imaging (DWI) for evaluation of radiotherapeutic effects on rabbit VX2 tumor model. Methods Sixteen New Zealand white rabbits... Objective To investigate the feasibility of magnetic resonance (MR) diffusion weighted imaging (DWI) for evaluation of radiotherapeutic effects on rabbit VX2 tumor model. Methods Sixteen New Zealand white rabbits received a subcutaneous implantation of VX2 tumor cell suspension 0.5 mL (4× 10^7 ceUs/mL) in their right thighs to set up tumor model. And 2 weeks later they were randomly divided into therapy group (Group T, n = 10) and control group (Group C, n = 6). Group T received radiotherapy at a single dose of 10 Gy. MR imaging (MRI) scan including short TI inversion recovery echo-planar imaging DWI, T1-weighted imaging (T1WI) and T2-weighted imaging (T2WI) sequences were performed 1 day prior to as well as 1 day, 2 days, 3 days and 7 days after radiotherapy. Group C received only MRI scan at the same time points without any treatment. MRI appearance on T2WI, TlWI, and DWI images was compared and tumor volume was calculated. Apparent diffusion coefficient (ADC) values of the tumor were evaluated in all cases. HE staining was used for pathological study. Results Necrosis (n = 8) and hemorrhage (n = 2) were seen gradually on T2WI and T1WI images of Group T after time point of day 2 after irradiation. In Group C, no obvious necrosis was found until day 7. There was no significant difference in tumor volume between the two groups before radiotherapy. After radiotherapy, tumors in Group T showed a gradual growth but not as obvious as Group C. There was a significant difference in tumor volume between the two groups from day 2 on (P 〈 0.05). ADC value changed dramatically fight from the 1st day after radiotherapy in Group T [(0.99 ± 0.15) ×10^-3 mm^2/s for 1 day before radiotherapy, (1.23 ± 0.08) ×10^-3 , (1.45 ± 0.07) ×10^-3 , (1.63 ± 0.06) ×10^-3 , and (2.02 ± 0.18) ×10^-3 mm^2 for day 1, 2, 3, and 7]; and ADC value had no significant changes after radiotherapy in Group C except day 7 [(1.07±0.08) ×10^-3 mm^2 for 1 day before radiotherapy, (1.03 ± 0.04)×10^-3 , (1.05 ± 0.02)×10^-3 , (1.05 ± 0.05) ×10^-3 , and (0.95 ± 0.07) ×10^-3 mm^2 for day 1, 2, 3, and 7]. There was significant difference in ADC value between the two groups for each time point after radiotherapy (P 〈 0.01). Pathological study showed that the number of viable tumor cells in Group T decreased 1 day after radiotherapy, and the inflammatory cell infiltration was marked and almost all viable tumor cells disappeared by day 7 after radiotherapy. Conclusions DWI is a new promising technique for monitoring radiotherapy outcomes. ADC value may give a prior clue on physiological changes of radiotherapy before routine MRI could tell. 展开更多
关键词 diffusion magnetic resonance imaging RADIOTHERAPY animal experiment
暂未订购
上一页 1 2 6 下一页 到第
使用帮助 返回顶部