期刊文献+
共找到201,285篇文章
< 1 2 250 >
每页显示 20 50 100
Correction: MicroRNA-329-3p inhibits the Wnt/β-catenin pathway and proliferation of osteosarcoma cells by targeting transcription factor 7-like 1
1
作者 HUI SUN MASANORI KAWANO +4 位作者 TATSUYA IWASAKI ICHIRO ITONAGA YUTA KUBOTA HIROSHI TSUMURA KAZUHIRO TANAKA 《Oncology Research》 SCIE 2024年第8期1369-1370,共2页
In the article‘MicroRNA-329-3p inhibits the Wnt/β-catenin pathway and proliferation of osteosarcoma cells by targeting transcription factor 7-like 1’(Oncology Research,2024,Vol.32,No.3,pp.463−476.doi:10.32604/or.20... In the article‘MicroRNA-329-3p inhibits the Wnt/β-catenin pathway and proliferation of osteosarcoma cells by targeting transcription factor 7-like 1’(Oncology Research,2024,Vol.32,No.3,pp.463−476.doi:10.32604/or.2023.044085),there was an error in the compilation of Fig.8D.We have revised Fig.8D to correct this error.A corrected version of Fig.8 is provided.This correction does not change any results or conclusions of the article.We apologize for any inconvenience caused. 展开更多
关键词 osteosarcoma CORRECTION revised
下载PDF
Alterations in Serum Lipids and Lipoproteins Induced by Neoadjuvant Chemotherapy in Patients with Osteosarcoma around the Knee Joint:A Retrospective Analysis
2
作者 Su-guo WANG Yong-gang WANG +8 位作者 Guo-wei QIAN Li-na TANG Xin ZHOU Dong-dong CHENG Chen-liang ZHOU Qing-cheng YANG Zan SHEN Gao-zhong HUANG Hong-tao LI 《Current Medical Science》 SCIE CAS 2024年第4期741-747,共7页
Objective To investigate the serum lipid profiles of patients with localized osteosarcoma around the knee joint before and after neoadjuvant chemotherapy.Methods After retrospectively screening the data of 742 patient... Objective To investigate the serum lipid profiles of patients with localized osteosarcoma around the knee joint before and after neoadjuvant chemotherapy.Methods After retrospectively screening the data of 742 patients between January 2007 and July 2020,50 patients aged 13 to 39 years with Enneking stage II disease were included in the study.Serum lipid levels,including total cholesterol(TC),triglycerides(TG),high-density lipoprotein cholesterol(HDL-C),low-density lipoprotein cholesterol(LDL-C),lipoprotein-α[Lp(a)],and apolipoprotein A1,B,and E(ApoA1,ApoB,and ApoE),and clinicopathological characteristics were collected before and after neoadjuvant chemotherapy.Results The mean levels of TC,TG,and ApoB were significantly increased following neoadjuvant chemotherapy(16%,38%,and 20%,respectively,vs.pretreatment values;P<0.01).The mean levels of LDL-C and ApoE were also 19%and 16%higher,respectively(P<0.05).No correlation was found between the pretreatment lipid profile and the histologic response to chemotherapy.An increase in Lp(a)was strongly correlated with the Ki-67 index(R=0.31,P=0.023).Moreover,a trend toward longer disease-free survival(DFS)was observed in patients with decreased TG and increased LDL-C following chemotherapy,although this difference was not statistically significant(P=0.23 and P=0.24,respectively).Conclusion Significant elevations in serum lipids were observed after neoadjuvant chemotherapy in patients with localized osteosarcoma.There was no prognostic significance of pretreatment serum lipid levels on histologic response to neoadjuvant chemotherapy.The scale of increase in serum Lp(a)might have a potential prognostic role in osteosarcoma.Patients with increased LDL-C or reduced TG after chemotherapy seem to exhibit a trend toward favorable DFS. 展开更多
关键词 osteosarcoma neoadjuvant chemotherapy serum lipids
下载PDF
Prognositic value of anoikis and tumor immune microenvironment-related gene in the treatment of osteosarcoma
3
作者 WANG Dong DENG Qing +7 位作者 PENG Yi TONG Zhaochen LI Zixin HUANG Liping ZENG Jin LI Jinsong MIAO Jinglei CHEN Shijie 《中南大学学报(医学版)》 CAS CSCD 北大核心 2024年第5期758-774,共17页
Objective:Osteosarcoma is a highly aggressive primary malignant bone tumor commonly seen in children and adolescents,with a poor prognosis.Anchorage-dependent cell death(anoikis)has been proven to be indispensable in ... Objective:Osteosarcoma is a highly aggressive primary malignant bone tumor commonly seen in children and adolescents,with a poor prognosis.Anchorage-dependent cell death(anoikis)has been proven to be indispensable in tumor metastasis,regulating the migration and adhesion of tumor cells at the primary site.However,as a type of programmed cell death,anoikis is rarely studied in osteosarcoma,especially in the tumor immune microenvironment.This study aims to clarify prognostic value of anoikis and tumor immune microenvironment-related gene in the treatment of osteosarcoma.Methods:Anoikis-related genes(ANRGs)were obtained from GeneCards.Clinical information and ANRGs expression profiles of osteosarcoma patients were sourced from the therapeutically applicable research to generate effective therapies and Gene Expression Omnibus(GEO)databases.ANRGs highly associated with tumor immune microenvironment were identified by the estimate package and the weighted gene coexpression network analysis(WGCNA)algorithm.Machine learning algorithms were performed to construct long-term survival predictive strategy,each sample was divided into high-risk and low-risk subgroups,which was further verified in the GEO cohort.Finally,based on single-cell RNA-seq from the GEO database,analysis was done on the function of signature genes in the osteosarcoma tumor microenvironment.Results:A total of 51 hub ANRGs closely associated with the tumor microenvironment were identified,from which 3 genes(MERTK,BNIP3,S100A8)were selected to construct the prognostic model.Significant differences in immune cell activation and immune-related signaling pathways were observed between the high-risk and low-risk groups based on tumor microenvironment analysis(all P<0.05).Additionally,characteristic genes within the osteosarcoma microenvironment were identified in regulation of intercellular crosstalk through the GAS6-MERTK signaling pathway.Conclusion:The prognostic model based on ANRGs and tumor microenvironment demonstrate good predictive power and provide more personalized treatment options for patients with osteosarcoma. 展开更多
关键词 ANOIKIs tumor immune microenvironment BIOINFORMATICs PROGNOsIs osteosarcoma
下载PDF
Hydroxysafflor yellow A induced ferroptosis of Osteosarcoma cancer cells by HIF-1α/HK2 and SLC7A11 pathway
4
作者 YIWEN ZHU LIU YANG +4 位作者 YING YU YING XIONG PING XIAO XIAO FU XIN LUO 《Oncology Research》 SCIE 2024年第5期899-910,共12页
Osteosarcoma is a very serious primary bone cancer with a high death rate and a dismal prognosis.Since there is no permanent therapy for this condition,it is necessary to develop a cure.Therefore,this investigation wa... Osteosarcoma is a very serious primary bone cancer with a high death rate and a dismal prognosis.Since there is no permanent therapy for this condition,it is necessary to develop a cure.Therefore,this investigation was carried out to assess the impacts and biological functions of hydroxysafflor yellow A(HYSA)in osteosarcoma cell lines(MG63).In this investigational study,MG63 cells were utilized.Microarray experiments,quantitative polymerase chain reaction(qPCR),immunofluorescent staining,extracellular acidification rate(ECAR),oxygen consumption rate(OCR),glucose consumption,lactate production,and ATP levels,proliferation assay,5-Ethynyl-2′-deoxyuridine(EDU)staining,and Western blot were performed.In MG63 cells,HYSA lowered cell proliferation and metastasis rates,suppressed EDU cell number,and enhanced caspase-3/9 activity levels.HYSA reduced the Warburg effect and induced ferroptosis(FPT)in MG63 cells.Inhibiting ferroptosis diminished HYSA’s anti-cancer activities in MG63 cells.The stimulation of the HIF-1α/SLC7A11 pathway decreased HYSA’s anti-cancer activities in MG63 cells.HIF-1αis one target spot for HYSA in a model of osteosarcoma cancer(OC).HYSA altered HIF-1α’s thermophoretic activity;following binding with HYSA,HIF-1α’s melting point increased from~55°C to~60°C.HYSA significantly enhanced the thermal stability of exogenous WT HIF-1αwhile not affecting Mut HIF-1α,suggesting that ARG-311,GLY-312,GLN-347,and GLN-387 may be involved in the interaction between HIF-1αand HYSA.Conclusively,our study revealed that HYSA induced FPT and reduced the Warburg effect of OC through mitochondrial damage by HIF-1α/HK2/SLC7A11 pathway.HYSA is a possible therapeutic option for OC or other cancers. 展开更多
关键词 Hydroxysafflor yellow A osteosarcoma HIF-1Α FPT
下载PDF
Exploring the effects of taurolidine on tumor weight and microvessel density in a murine model of osteosarcoma
5
作者 LISANNE K.A.NEIJENHUIS LEUTA L.NAUMANN +2 位作者 SONIA A.M.FERKEL SAMUEL J.S.RUBIN STEPHAN ROGALLA 《Oncology Research》 SCIE 2024年第7期1163-1172,共10页
Background:Osteosarcoma is the most common malignant primary bone tumor.The prognosis for patients with disseminated disease remains very poor despite recent advancements in chemotherapy.Moreover,current treatment reg... Background:Osteosarcoma is the most common malignant primary bone tumor.The prognosis for patients with disseminated disease remains very poor despite recent advancements in chemotherapy.Moreover,current treatment regimens bear a significant risk of serious side effects.Thus,there is an unmet clinical need for effective therapies with improved safety profiles.Taurolidine is an antibacterial agent that has been shown to induce cell death in different types of cancer cell lines.Methods:In this study,we examined both the antineoplastic and antiangiogenic effects of taurolidine in animal models of osteosarcoma.K7M2 murine osteosarcoma cells were injected,both intramuscular and intraperitoneal,into 60 BALB/c mice on day zero.Animals were then randomized to receive treatment with taurolidine 2%(800 mg/kg),taurolidine 1%(400 mg/kg),or NaCl 0.9%control for seven days by intravenous or intraperitoneal administration.Results:After 35 days,mice were euthanized,and the tumors were harvested for analysis.Eighteen mice were excluded from the analysis due to complications.Body weight was significantly lower in the 2%taurolidine intraperitoneal treatment group from day 9 to 21,consistent with elevated mortality in this group.Intraperitoneal tumor weight was significantly lower in the 1%(p=0.003)and 2%(p=0.006)intraperitoneal taurolidine treatment groups compared to the control.No antineoplastic effects were observed on intramuscular tumors or for intravenous administration of taurolidine.There were no significant differences in microvessel density or mitotic rate between treatment groups.Reduced body weight and elevated mortality in the 2%taurolidine intraperitoneal group suggest that the lower 1%dose is preferable.Conclusions:In conclusion,there is no evidence of antiangiogenic activity,and the antitumor effects of taurolidine on osteosarcoma observed in this study are limited.Moreover,its toxic profile grants further evaluation.Given these observations,further research is necessary to refine the use of taurolidine in osteosarcoma treatment. 展开更多
关键词 osteosarcoma TAUROLIDINE Cancer treatment CHEMOTHERAPY Murine models
下载PDF
Large Conventional Osteosarcoma of the Proximal Humerus in a 13-Year-Old Child: Case Report
6
作者 Lucienne Irène Patricia Ondima Rhodia Hélène Bosseba Missengue +7 位作者 Cardinale Princilia Okiemy Niendet Nuptia Erica Akobande Jean Claude Mieret Caryne Mboutol-Mandavo Redy Atipo Galloye Judith Nsondé Malanda Jennifer Mave Sirimé Ngandzo Fabien Mouamba 《Open Journal of Pediatrics》 2024年第2期297-304,共8页
Introduction: Osteosarcoma is the most common primary malignant bone tumor in children. It is highly aggressive and has a poor prognosis. A late presentation modifies and makes difficult the management affecting the s... Introduction: Osteosarcoma is the most common primary malignant bone tumor in children. It is highly aggressive and has a poor prognosis. A late presentation modifies and makes difficult the management affecting the survival of children. We report the case of a large conventional osteosarcoma in a 13-year-old girl. Case Presentation: Adolescent girl admitted for painful swelling of the left shoulder with absolute functional impotence of the thoracic limb and severe anemia. The painful swelling was thought to have been caused by a minor trauma that had occurred six months previously. The patient’s general condition was poor, and she presented with a large, shiny, painful mass over the shoulder and upper 2/3 of the left arm, measuring 28 cm long by 28 cm wide and 57 cm in circumference, and a large fistulous axillary adenopathy. CT scan showed a tumour lesion of the left humerus with liver and lung metastases, raising suspicion of osteogenic osteosarcoma. The tumor was classified according to TNM staging: T2N1M1(a + b). Management was modified when uncontrolled bleeding developed. It consisted of an extended amputation of the left thoracic limb. Pathological analysis showed a high-grade conventional osteosarcoma. Quality improvement was obtained for thirty days, followed by the onset of dyspnea. The evolution was towards death at forty days post-operatively. Conclusion: Osteosarcoma is a highly aggressive cancer. Delayed treatment leads to a fatal outcome. Early diagnosis is one of the challenges to be met in order to improve survival. 展开更多
关键词 osteosarcoma CHILD CONVENTIONAL Case Report
下载PDF
Codelivery of anti-CD47 antibody and chlorin e6 using a dual pH-sensitive nanodrug for photodynamic immunotherapy of osteosarcoma
7
作者 JIJIE XIAO HONG XIAO +4 位作者 YUJUN CAI JIANWEI LIAO JUE LIU LIN YAO SHAOLIN LI 《Oncology Research》 SCIE 2024年第4期691-702,共12页
Osteosarcoma is a malignant tumor originating from bone tissue that progresses rapidly and has a poor patient prognosis.Immunotherapy has shown great potential in the treatment of osteosarcoma.However,the immunosuppre... Osteosarcoma is a malignant tumor originating from bone tissue that progresses rapidly and has a poor patient prognosis.Immunotherapy has shown great potential in the treatment of osteosarcoma.However,the immunosuppressive microenvironment severely limits the efficacy of osteosarcoma treatment.The dual pH-sensitive nanocarrier has emerged as an effective antitumor drug delivery system that can selectively release drugs into the acidic tumor microenvironment.Here,we prepared a dual pH-sensitive nanocarrier,loaded with the photosensitizer Chlorin e6(Ce6)and CD47 monoclonal antibodies(aCD47),to deliver synergistic photodynamic and immunotherapy of osteosarcoma.On laser irradiation,Ce6 can generate reactive oxygen species(ROS)to kill cancer cells directly and induces immunogenic tumor cell death(ICD),which further facilitates the dendritic cell maturation induced by blockade of CD47 by aCD47.Moreover,both calreticulin released during ICD and CD47 blockade can accelerate phagocytosis of tumor cells by macrophages,promote antigen presentation,and eventually induce T lymphocyte-mediated antitumor immunity.Overall,the dual pH-sensitive nanodrug loaded with Ce6 and aCD47 showed excellent immune-activating and anti-tumor effects in osteosarcoma,which may lay the theoretical foundation for a novel combination model of osteosarcoma treatment. 展开更多
关键词 IMMUNOTHERAPY osteosarcoma Nanodrug Photodynamic therapy CD47
下载PDF
MicroRNA-329-3p inhibits the Wnt/β-catenin pathway and proliferation of osteosarcoma cells by targeting transcription factor 7-like 1
8
作者 Hur SUN MASANORI KAWANO +4 位作者 TATSUYA IWASAKI ICHRO ITONAGA YUTA KUBOTA HROSHI TSUMURA KAZUHRO TANAKA 《Oncology Research》 SCIE 2024年第3期463-476,共14页
An important factor in the emergence and progre sion of osteosarcoma(OS)is the dysregulated expression of microRNAs(miRNAs).Transcription factor 7-like 1(TCF7LI),a member of the T cell factor/lymphoid enhancer factor(... An important factor in the emergence and progre sion of osteosarcoma(OS)is the dysregulated expression of microRNAs(miRNAs).Transcription factor 7-like 1(TCF7LI),a member of the T cell factor/lymphoid enhancer factor(TCF/LEF)transcription factor family,interacts with the Wnt signaling pathway regulator β-catenin and acts as a DNA-specific binding protein.This study sought to elucidate the impact of the interaction between miR 3293p and TCF7L1 on.the growth and apoptosis of OS and analyze the regulatory expression relationship between miRNA and mRNA in osteosarcoma cells using a variety of approaches.MiR329-3p was significantly downregulated,while TCF7L1 was considerably up-regulated in all examined OS cell lines.Additionally,a clinical comparison study was performed using the TCGA database.Subsequently,the regulatory relationship between miR-329-3p and TCF7L1 on the proliferation and apoptosis of OS cells was verified through in vitro and in vivo experiments.When miR 329-3p was transfected into the OS cell line,the expression of TCF7L1 decreased,the proliferation of OS cells was inhibited,the cytoskeleton disintegrated,and the nucleus condensed to fom apoptotic bodies.The expression of proteins that indicate apoptosis increased simultaneously.The cell cycle was arrested in the G0/G1 phase,and the G1/S transition was blocked.The introduction of miR 3293p also inhibited downstream Cyclin D1 of the Wnt pathway.Xenograf experiments indicated that the overexpression of miR-329-3p signi ficanly inhibited the growth of OS xenografts in nude mice,and the expression of TCF7L1 and C-Myc in tumor tssues decreased.MiR 329-3p was significantly reduced in OS cells and played a suppressive role in tumorigenesis and proliferation by targeting TCF7L1 both in vitro and in vivo.Osteosarcoma cell cycle arrest and pathway inhibition were observed upon the regulation of TCF7LI by miR 3293p.Summarizing these results,it can be inferred that miR.3293p exerts anticancer efects in osteosarcoma by inhibiting TCF7L1. 展开更多
关键词 MiR-329-3p TCF7L1 Wnt/β-catenin pathway osteosarcoma PROLIFERATION
下载PDF
Mitochondrial dysfunction and programmed cell death in osteosarcoma
9
作者 Ke Zhang Ming-Yang Jiang +2 位作者 Kai-Cheng Liu Yong-Heng Dai Zhan-Dong Bo 《Journal of Nutritional Oncology》 2024年第2期37-45,共9页
Osteosarcoma is the most prevalent primarymalignant bone tumor,primarily affecting adolescents aged 15–25 years.It is characterized by a high recurrence rate,poor prognosis,and lack of important biomarkers.Significan... Osteosarcoma is the most prevalent primarymalignant bone tumor,primarily affecting adolescents aged 15–25 years.It is characterized by a high recurrence rate,poor prognosis,and lack of important biomarkers.Significant mitochondrial dysfunction in osteosarcoma cells has been widely reported by recent studies.Dysfunctional mitochondria occupy an important position in cellularmetabolic reprogramming,immune microenvironment regulation,and programmed cell death.Therefore,targeting mitochondrial dysfunction may represent a new mechanism to overcome therapeutic barriers in the treatment of osteosarcoma and provides crucial target molecules for further development of targeted therapies and immunotherapies.The present article summarizes the recent reports of mitochondrial dysfunction in osteosarcoma and links it to various programmed cell death mechanisms,aiming to provide the basis for further clinical practice. 展开更多
关键词 osteosarcoma Mitochondrial function Programmed cell death MITOPHAGY Metabolic reprogramming
下载PDF
S型异质结光催化剂ZnFe_(2)O_(4)/WO_(3)的构筑及光催化还原CO_(2)性能 被引量:1
10
作者 刘平 朱成才 +1 位作者 李艳阳 要红昌 《无机化学学报》 SCIE CSCD 北大核心 2024年第1期197-208,共12页
通过在WO_(3)纳米片表面负载ZnFe_(2)O_(4)纳米颗粒,构建了一系列S型异质结光催化剂ZnFe_(2)O_(4)/WO_(3),并研究了其光催化CO_(2)还原性能。在没有助催化剂和牺牲剂的条件下,所制备的ZnFe_(2)O_(4)/WO_(3)复合材料可对CO_(2)与水蒸汽... 通过在WO_(3)纳米片表面负载ZnFe_(2)O_(4)纳米颗粒,构建了一系列S型异质结光催化剂ZnFe_(2)O_(4)/WO_(3),并研究了其光催化CO_(2)还原性能。在没有助催化剂和牺牲剂的条件下,所制备的ZnFe_(2)O_(4)/WO_(3)复合材料可对CO_(2)与水蒸汽进行光催化反应。优化后的材料光照5 h后CO_(2)还原产物CO和CH_(4)的产量分别为7.87和4.88μmol·g^(-1)。相对于单相组分,CO和CH_(4)的产量明显提高。光催化活性的提高,归因于ZnFe_(2)O_(4)和WO_(3)异质结的形成以及光生载流子的S型电荷传输模式。 展开更多
关键词 CO_(2)还原 光催化活性 ZnFe_(2)O_(4)/WO_(3) 异质结 s型电荷传输模式
下载PDF
2022年四川芦山M_(S)6.1地震前应力状态研究
11
作者 张致伟 曾宪伟 +4 位作者 王迪 路茜 王玮铭 杨鹏 龙锋 《地震研究》 CSCD 北大核心 2024年第4期483-492,共10页
为研究2022年6月1日四川芦山M_(S)6.1地震的孕育和发生过程,采用CAP方法反演了2013年芦山M_(S)7.0主震及M_(S)≥5.0余震的震源机制解,并基于应力张量方差与b值时空分布特征,探讨了芦山M_(S)6.1地震的力学机制和震源区的应力状态。结果表... 为研究2022年6月1日四川芦山M_(S)6.1地震的孕育和发生过程,采用CAP方法反演了2013年芦山M_(S)7.0主震及M_(S)≥5.0余震的震源机制解,并基于应力张量方差与b值时空分布特征,探讨了芦山M_(S)6.1地震的力学机制和震源区的应力状态。结果表明:2022年芦山M_(S)6.1地震震源机制表现出与2013年芦山M_(S)7.0主震和5级余震相似的逆冲型破裂特征,压应力轴方位与龙门山断裂带南段区域应力场一致。2013年芦山M_(S)7.0地震后震中及附近的应力张量方差和b值长期处于低值状态,2022年芦山M_(S)6.1地震前震中及附近出现了应力张量方差和b值的低值异常,表明芦山余震区处于较高的应力水平。分析认为:巴颜喀拉块体持续东向运动受到华南块体的阻挡,震中所在区域长期受挤压逆冲作用,从而使芦山余震区长期处于应力积累的状态,芦山M_(S)6.1地震也是在这种动力学背景下发生的。 展开更多
关键词 芦山M_(s)6.1地震 芦山M_(s)7.0地震 震源机制解 应力张量方差 B值 应力状态
下载PDF
阴道卷曲乳杆菌S层蛋白多样性研究
12
作者 李娜 刘好静 +2 位作者 张婷 张茜 李娇 《川北医学院学报》 CAS 2024年第9期1167-1170,1175,共5页
目的:分析比较西安市女性阴道卷曲乳杆菌S层蛋白的多样性及NCBI数据库中阴道来源卷曲乳杆菌S层蛋白的多样性。方法:选取100例妇科患者的阴道分泌物标本作为研究对象,从其中10例标本中分离得到480株卷曲乳杆菌,其中两株卷曲乳杆菌S层蛋... 目的:分析比较西安市女性阴道卷曲乳杆菌S层蛋白的多样性及NCBI数据库中阴道来源卷曲乳杆菌S层蛋白的多样性。方法:选取100例妇科患者的阴道分泌物标本作为研究对象,从其中10例标本中分离得到480株卷曲乳杆菌,其中两株卷曲乳杆菌S层蛋白有明显差异,对其进行全基因组测序;并从NCBI数据库中下载人阴道源的卷曲乳杆菌全基因组数据,分析并比较西安市来源与数据库来源的卷曲乳杆菌S层蛋白的多样性。结果:S层蛋白注释基因具有菌株内和菌株间的多样性,同一套基因组中有多个S层蛋白注释基因,菌株间的相似性偏差较大,通过系统发育分析发现,中国人阴道卷曲乳杆菌的S层蛋白基因与其他人种的具有系统发育相似性。结论:阴道卷曲乳杆菌S层蛋白具有菌种间和菌株间多样性的特征,不同人种的卷曲乳杆菌具有相似性。 展开更多
关键词 阴道 卷曲乳杆菌 s层蛋白 多样性
下载PDF
结合主动光源和改进YOLOv5s模型的夜间柑橘检测方法 被引量:2
13
作者 熊俊涛 霍钊威 +4 位作者 黄启寅 陈浩然 杨振刚 黄煜华 苏颖苗 《华南农业大学学报》 CAS CSCD 北大核心 2024年第1期97-107,共11页
【目的】解决夜间环境下遮挡和较小柑橘难以准确识别的问题,实现采摘机器人全天候智能化作业。【方法】提出一种结合主动光源的夜间柑橘识别方法。首先,通过分析主动光源下颜色特征不同的夜间柑橘图像,选择最佳的光源色并进行图像采集... 【目的】解决夜间环境下遮挡和较小柑橘难以准确识别的问题,实现采摘机器人全天候智能化作业。【方法】提出一种结合主动光源的夜间柑橘识别方法。首先,通过分析主动光源下颜色特征不同的夜间柑橘图像,选择最佳的光源色并进行图像采集。然后,提出一种夜间柑橘检测模型BI-YOLOv5s,该模型采用双向特征金字塔网络(Bi-FPN)进行多尺度交叉连接和加权特征融合,提高对遮挡和较小果实的识别能力;引入Coordinate attention(CA)注意力机制模块,进一步加强对目标位置信息的提取;采用融入Transformer结构的C3TR模块,在减少计算量的同时更好地提取全局信息。【结果】本文提出的BI-YOLOv5s模型在测试集上的精准率、召回率、平均准确率分别为93.4%、92.2%和97.1%,相比YOLOv5s模型分别提升了3.2、1.5和2.3个百分点。在所采用的光源色环境下,模型对夜间柑橘识别的正确率为95.3%,相比白光环境下提高了10.4个百分点。【结论】本文提出的方法对夜间环境下遮挡和小目标柑橘的识别具有较高的准确性,可为夜间果蔬智能化采摘的视觉精准识别提供技术支持。 展开更多
关键词 柑橘 夜间检测 主动光源 双向特征金字塔网络 YOLOv5s HsV颜色空间
下载PDF
基于改进YOLOv5s的不同成熟度苹果目标检测方法 被引量:1
14
作者 王勇 陶兆胜 +2 位作者 石鑫宇 伍毅 吴浩 《南京农业大学学报》 CAS CSCD 北大核心 2024年第3期602-611,共10页
[目的]本文旨在解决在自然环境下不同成熟度苹果目标检测精度较低的问题。[方法]提出了一种改进的YOLOv5s模型SODSTR-YOLOv5s(YOLOv5s with small detection layer and omni-dimensional dynamic convolution and swin transformer bloc... [目的]本文旨在解决在自然环境下不同成熟度苹果目标检测精度较低的问题。[方法]提出了一种改进的YOLOv5s模型SODSTR-YOLOv5s(YOLOv5s with small detection layer and omni-dimensional dynamic convolution and swin transformer block),用于不同成熟度苹果检测。首先改进YOLOv5s的多尺度目标检测层,在Prediction中构建检测160×160特征图的检测头,提高小尺寸的不同成熟度苹果的检测精度;其次在Backbone结构中融合Swin Transformer Block,加强同级成熟度的苹果纹理特征融合,弱化纹理特征分布差异带来的消极影响,提高模型泛化能力;最后将Neck结构的Conv模块替换为动态卷积模块ODConv,细化局部特征映射,实现局部苹果细粒度特征的充分提取。基于不同成熟度苹果数据集进行试验,验证改进模型的性能。[结果]改进模型SODSTR-YOLOv5s检测的精确率、召回率、平均精度均值分别为89.1%、95.5%、93.6%,高、中、低成熟度苹果平均精度均值分别为94.1%、93.1%、93.7%,平均检测时间为16 ms,参数量为7.34 M。相比于YOLOv5s模型,改进模型SODSTR-YOLOv5s精确率、召回率、平均精度均值分别提高了3.8%、5.0%、2.9%,参数量和平均检测时间分别增加了0.32 M和5 ms。[结论]改进模型SODSTR-YOLOv5s提升了在自然环境下对不同成熟度苹果的检测能力,能较好地满足实际采摘苹果的检测要求。 展开更多
关键词 苹果 成熟度 目标检测 YOLOv5s 深度学习 自然环境
下载PDF
献血者HBVs基因变异的生物信息学分析
15
作者 范加诚 李青 +2 位作者 陈秀丽 刘世香 陈烨 《中国输血杂志》 CAS 2024年第8期933-939,共7页
目的分析HBV DNA+/HBsAg-献血者的传染性指标、S区基因序列突变情况及生物信息学特征变化。方法通过PCR方法筛查出1份HBV DNA+/HBsAg-的标本,应用酶联免疫和化学发光方法检测该标本乙肝病毒5项指标,对该标本HBVs区基因片段测序并分析变... 目的分析HBV DNA+/HBsAg-献血者的传染性指标、S区基因序列突变情况及生物信息学特征变化。方法通过PCR方法筛查出1份HBV DNA+/HBsAg-的标本,应用酶联免疫和化学发光方法检测该标本乙肝病毒5项指标,对该标本HBVs区基因片段测序并分析变异情况,应用分析软件对所测序列进行生物信息学分析。结果该标本HBV DNA+、HBsAg-、HBsAb+、HBeAg+、HBeAb-、HBcAb+;HBVs区基因序列内发生氨基酸单位点突变(P151L),空间结构发生改变。结论HBVs区基因序列空间结构改变,可能是导致检测结果出现血清学HBsAg-/HBsAb+/HBV DNA+的原因。 展开更多
关键词 HBV OBI s基因 献血者 生物信息学
下载PDF
在片S参数计量比对结果浅析
16
作者 刘晨 高岭 +7 位作者 栾鹏 陈婷 黄英龙 李艳奎 金诚 邹喜跃 陆景 陈科元 《计量学报》 CSCD 北大核心 2024年第9期1401-1406,共6页
中国电子科技集团公司第十三研究所作为主导实验室开展了在片S参数计量比对工作,对参比实验室提交的在片S参数测量结果进行了汇总分析,并用E_n值对各参比实验室测量结果进行了评价。通过在片S参数计量比对,确保了量值传递的准确、可靠,... 中国电子科技集团公司第十三研究所作为主导实验室开展了在片S参数计量比对工作,对参比实验室提交的在片S参数测量结果进行了汇总分析,并用E_n值对各参比实验室测量结果进行了评价。通过在片S参数计量比对,确保了量值传递的准确、可靠,特别是对在片S参数测量不确定度的主要来源统一了认识。同时也为业内提供了在片S参数测量一致性的比较平台。 展开更多
关键词 无线电计量 在片s参数 计量比对 矢量网络分析仪
下载PDF
基于数值模拟的高速公路S型曲线积水规律分析
17
作者 吴文亮 曾威凯 +1 位作者 李智 王晓飞 《华南理工大学学报(自然科学版)》 EI CAS CSCD 北大核心 2024年第8期56-64,共9页
S型曲线由于特殊的线型几何特征形成了易积水的路面区域,对于积水规律的掌握有利于在设计和建造阶段提前预防和处理积水路段的危害。该文基于计算流体力学软件Fluent,结合计算流体力学分析中基于欧拉-拉格朗日方法的欧拉液膜模型EWF(Eul... S型曲线由于特殊的线型几何特征形成了易积水的路面区域,对于积水规律的掌握有利于在设计和建造阶段提前预防和处理积水路段的危害。该文基于计算流体力学软件Fluent,结合计算流体力学分析中基于欧拉-拉格朗日方法的欧拉液膜模型EWF(Eulerian Wall Film),针对精细化处理的典型S型曲线双向多车道道路模型进行模拟计算。模拟包含了几何特征与降雨量等不同变量因素,得出了积水的水膜厚度以及流速分布规律。模拟结果表明:在降雨阶段,S型曲线横坡坡度0%~1%路段为积水路段,横坡坡度1%~2%路段为易积水路段,横坡坡度大于2%的路段积水情况受到降雨强度影响;在排水阶段,S型曲线横坡坡度0%~1%路段为排水困难路段,横坡坡度1%~2%路段为排水不畅路段,横坡坡度大于2%的路段排水顺畅,在排水时间结束时,路面在不同的几何条件和降雨条件下均能将积水排除至水膜厚度小于2 cm,横坡的大小与渐变影响了积水的横向分布与纵向分布,横向呈现中间高两边低、横断面上标高大的位置水膜厚度小和标高小的位置水膜厚度大的水膜厚度分布规律,总体呈现S型的分布规律;水膜流速在积水阶段呈现纵向上中间低两边高、水膜厚度大则水膜流速大的水膜厚度分布规律,在排水阶段则为纵向上中间高两边低的水膜流速分布规律。道路宽度影响了降雨落到路面的积水总量,进而对积水水膜厚度产生了影响;超高缓和率则主要使得积水路段、易积水路段增长,从而影响了积水分布的范围。 展开更多
关键词 计算流体力学 s型曲线 路面积水 积水规律
下载PDF
S31603复合板压力容器点蚀行为试验研究 被引量:1
18
作者 宋晓俊 杨忠武 +4 位作者 豆磊 张烜玮 魏西尧 谭中炜 郭睿朋 《压力容器》 北大核心 2024年第3期8-16,共9页
针对S31603复合板压力容器不锈钢层不同点蚀深度的发展进程及穿透至碳钢层后的电偶腐蚀风险,通过预制不同点蚀深度的S31603复合板试片组,分别在实验室和现场S31603复合板压力容器内进行腐蚀试验,并对试片进行宏观分析、低倍观察、高倍... 针对S31603复合板压力容器不锈钢层不同点蚀深度的发展进程及穿透至碳钢层后的电偶腐蚀风险,通过预制不同点蚀深度的S31603复合板试片组,分别在实验室和现场S31603复合板压力容器内进行腐蚀试验,并对试片进行宏观分析、低倍观察、高倍观察及腐蚀产物表征分析。结果表明,S31603复合板预制的点蚀坑深度穿透至碳钢层时发生了明显的电偶腐蚀,实验室腐蚀试验和现场试验最高点蚀速率分别达到4.954,1.023 mm/a;用S31603复合板试片预制的点蚀坑深度穿透至碳钢层后碳钢优先发生电偶腐蚀;S31603复合板试片预制的点蚀坑深度处于不锈钢层时腐蚀轻微,也未萌生新的点蚀,相邻点蚀坑之间也未见明显的腐蚀影响。在含Cl-的酸性腐蚀性介质环境下,当S31603复合板压力容器点蚀深度处于不锈钢层时腐蚀轻微,当点蚀深度穿透至碳钢层后,会发生明显的电偶腐蚀,需要缩短S31603复合板压力容器开罐检修周期以保证安全使用。 展开更多
关键词 复合板压力容器 点蚀 s31603 腐蚀试验
下载PDF
基于CFS-YOLO算法的复杂工况环境下煤矸图像识别方法 被引量:1
19
作者 李德永 王国法 +2 位作者 郭永存 王爽 杨宇豪 《煤炭科学技术》 EI CAS CSCD 北大核心 2024年第6期226-237,共12页
针对煤矿高噪声、低照度、运动模糊与大批量煤矸混杂等复杂工况环境因素导致煤矸识别存在误检、漏检以及检测精度低的问题,提出一种基于CFS-YOLO算法的煤矸智能识别模型。采用ConvNeXt V2(Convolutional Neural Network with NeXt Units... 针对煤矿高噪声、低照度、运动模糊与大批量煤矸混杂等复杂工况环境因素导致煤矸识别存在误检、漏检以及检测精度低的问题,提出一种基于CFS-YOLO算法的煤矸智能识别模型。采用ConvNeXt V2(Convolutional Neural Network with NeXt Units Version 2)特征提取模块替换主干网络末端的2个C3(Cross Stage Partial Bottle Neck Mudule)模块,通过将掩码自动编码器(Masked Autoencoders,MAE)和全局响应归一化(Global Response Normalization,GRN)层添加到ConvNeXt架构中,有效缓解特征崩溃问题以及保持特征在网络传递过程中的多样性;采用Focal-EIOU(Focal and Efficient Intersection Over Union)损失函数替换原CIOU(Computer Intersection Over Union)损失函数,通过其Focal-Loss机制和调整样本权重的方式优化边界框回归任务中的样本不平衡问题,提高模型的收敛速度和定位精度;添加无参注意力机制(Simple Attention Mechanism,SimAM)于主干网络每个C3模块的后端,凭借其注意力权重自适应调整策略,提升模型对尺度变化较大或低分辨率煤矸目标关键特征的提取能力。通过消融试验和对比试验验证所提CFS-YOLO模型的有效性与优越性。试验结果表明:CFS-YOLO模型对于煤矸在煤矿高噪声、低照度、运动模糊与大批量煤矸混杂等复杂环境下的检测效果均得到有效提高,模型的平均精度均值达到90.2%,相较于原YOLOv5s模型的平均精度均值提高了3.7%,平均检测速度达到90.09 FPS,可充分满足煤矸实时检测的需求。同时与YOLOv5s、YOLOv7-tiny与YOLOv8n等6种YOLO系列算法相比,CFS-YOLO模型对煤矿复杂环境的适应性最强且综合检测性能最佳,可为煤矸的智能高效分选提供技术支持。 展开更多
关键词 YOLOv5s 煤矸识别 特征提取 损失函数 注意力机制
下载PDF
σ相对S32205双相不锈钢力学性能和耐蚀性的影响 被引量:1
20
作者 王良 彭荟宁 +4 位作者 赵攀 胡议文 周培山 郑华林 王斌 《材料热处理学报》 CAS CSCD 北大核心 2024年第4期113-121,共9页
通过JMatPro软件模拟计算和试验结合的方式研究了S32205双相不锈钢中σ相的析出行为及对其力学性能和耐蚀性的影响。结果表明:通过JMatPro软件模拟计算得到的S32205双相不锈钢σ相析出鼻尖温度为875℃。当S32205双相不锈钢在875℃保温0~... 通过JMatPro软件模拟计算和试验结合的方式研究了S32205双相不锈钢中σ相的析出行为及对其力学性能和耐蚀性的影响。结果表明:通过JMatPro软件模拟计算得到的S32205双相不锈钢σ相析出鼻尖温度为875℃。当S32205双相不锈钢在875℃保温0~90 min,σ相含量快速增加,当保温时间增加至90~120 min时,σ相含量缓慢上升,而当保温时间为120~240 min时σ相含量达到饱和,最大为6.1%,与模拟计算结果基本符合。随着保温时间逐渐增加,S32205双相不锈钢的屈服强度、抗拉强度及显微硬度先快速增加后逐渐保持稳定,而伸长率呈下降趋势,强度和硬度与σ相体积含量成正比关系,σ相强化机理由Orowan强化机制转变为σ相的高弹性应变能强化机制。不同σ含量的S32205双相不锈钢的电化学试验结果表明随着σ相的含量逐渐增多,基体越容易贫Cr, S32205双相不锈钢越容易产生腐蚀,耐蚀性逐渐降低。 展开更多
关键词 s32205双相不锈钢 Σ相 显微组织 力学性能 耐蚀性
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部