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Ethanol changes Nestin-promoter induced neural stem cells to disturb newborn dendritic spine remodeling in the hippocampus of mice 被引量:1
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作者 Guixiang Wang Wenjia Wang +7 位作者 Ye Zhang Xiaoying Gou Qingqing Zhang Yanmiao Huang Kuo Zhang Haotian Zhang Jingyu Yang Yuting Li 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第2期416-424,共9页
Adolescent binge drinking leads to long-lasting disorders of the adult central nervous system,particularly aberrant hippocampal neurogenesis.In this study,we applied in vivo fluorescent tracing using NestinCreERT2::Ro... Adolescent binge drinking leads to long-lasting disorders of the adult central nervous system,particularly aberrant hippocampal neurogenesis.In this study,we applied in vivo fluorescent tracing using NestinCreERT2::Rosa26-tdTomato mice and analyzed the endogenous neurogenesis lineage progression of neural stem cells(NSCs)and dendritic spine formation of newborn neurons in the subgranular zone of the dentate gyrus.We found abnormal orientation of tamoxifen-induced tdTomato+(tdTom^(+))NSCs in adult mice 2 months after treatment with EtOH(5.0 g/kg,i.p.)for 7 consecutive days.EtOH markedly inhibited tdTom^(+)NSCs activation and hippocampal neurogenesis in mouse dentate gyrus from adolescence to adulthood.EtOH(100 mM)also significantly inhibited the proliferation to 39.2%and differentiation of primary NSCs in vitro.Adult mice exposed to EtOH also exhibited marked inhibitions in dendritic spine growth and newborn neuron maturation in the dentate gyrus,which was partially reversed by voluntary running or inhibition of the mammalian target of rapamycinenhancer of zeste homolog 2 pathway.In vivo tracing revealed that EtOH induced abnormal orientation of tdTom+NSCs and spatial misposition defects of newborn neurons,thus causing the disturbance of hippocampal neurogenesis and dendritic spine remodeling in mice. 展开更多
关键词 ADOLESCENCE ADULTHOOD ETHANOL dentate gyrus EZH2 in vivo tracing lineage progression mTOR neural stem cell newborn dendritic spine newborn neurons
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Blastic plasmacytoid dendritic cell neoplasm:Two case reports 被引量:1
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作者 Yi-Qian Ma Zhan Sun +1 位作者 Yu-Mei Li Hui Xu 《World Journal of Clinical Oncology》 2024年第9期1207-1214,共8页
BACKGROUND Blastic plasmacytoid dendritic cell tumor(BPDCN)is a rare and highly invasive lymphohematopoietic tumor that originates from plasmacytoid dendritic cells.BPDCN has an extremely poor prognosis.Skin lesions a... BACKGROUND Blastic plasmacytoid dendritic cell tumor(BPDCN)is a rare and highly invasive lymphohematopoietic tumor that originates from plasmacytoid dendritic cells.BPDCN has an extremely poor prognosis.Skin lesions are usually the first manifestation of BPDCN,although the tumor may also invade the bone marrow,lymph nodes,peripheral blood,and other parts of the body,leading to several other manifestations,requiring further differentiation through skin biopsy and immunohistochemistry.CASE SUMMARY In the present paper,the cases of 2 patients diagnosed with BPDCN are discussed.The immunohistochemistry analysis of these 2 patients revealed positivity for CD4,CD56,and CD123.Currently,no standard chemotherapy regimen is available for BPDCN.Therefore,intensive therapy for acute lymphoblastic leukemia was applied as the treatment method for these 2 cases.CONCLUSION Although allogeneic bone marrow transplantation could be further effective in prolonging the median survival the ultimate prognosis was unfavorable.Future treatment modalities tailored for elderly patients will help prolong survival. 展开更多
关键词 Blastic plasmacytoid dendritic cell neoplasm SKIN CD4 CD56 CD123 Venetoclax Case report
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Relationship between Phenotypic Changes of Dendritic Cell Subsets and the Onset of Plateau Phase during Intermittent Interferon Therapy in Patients with CHB
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作者 YANG Liu WANG Shi Yu +13 位作者 JIANG Ting Ting DENG Wen CHANG Min WU Shu Ling CAO Wei Hua LU Yao SHEN Ge LIU Ru Yu GAO Yuan Jiao XU Meng Jiao HU Lei Ping ZHANG Lu XIE Yao LI Ming Hui 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2024年第3期303-314,共12页
Objective This study aimed to evaluate whether the onset of the plateau phase of slow hepatitis B surface antigen decline in patients with chronic hepatitis B treated with intermittent interferon therapy is related to... Objective This study aimed to evaluate whether the onset of the plateau phase of slow hepatitis B surface antigen decline in patients with chronic hepatitis B treated with intermittent interferon therapy is related to the frequency of dendritic cell subsets and expression of the costimulatory molecules CD40,CD80,CD83,and CD86.Method This was a cross-sectional study in which patients were divided into a natural history group(namely NH group),a long-term oral nucleoside analogs treatment group(namely NA group),and a plateau-arriving group(namely P group).The percentage of plasmacytoid dendritic cell and myeloid dendritic cell subsets in peripheral blood lymphocytes and monocytes and the mean fluorescence intensity of their surface costimulatory molecules were detected using a flow cytometer.Results In total,143 patients were enrolled(NH group,n=49;NA group,n=47;P group,n=47).The results demonstrated that CD141/CD1c double negative myeloid dendritic cell(DNmDC)/lymphocytes and monocytes(%)in P group(0.041[0.024,0.069])was significantly lower than that in NH group(0.270[0.135,0.407])and NA group(0.273[0.150,0.443]),and CD86 mean fluorescence intensity of DNmDCs in P group(1832.0[1484.0,2793.0])was significantly lower than that in NH group(4316.0[2958.0,5169.0])and NA group(3299.0[2534.0,4371.0]),Adjusted P all<0.001.Conclusion Reduced DNmDCs and impaired maturation may be associated with the onset of the plateau phase during intermittent interferon therapy in patients with chronic hepatitis B. 展开更多
关键词 CHB dendritic cells Intermittent Interferon Therapy Plateau Phase
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The current role of dendritic cells in the progression and treatment of colorectal cancer
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作者 Yuanci Zhang Songtao Ji +7 位作者 Ge Miao Shuya Du Haojia Wang Xiaohua Yang Ang Li Yuanyuan Lu Xin Wang Xiaodi Zhao 《Cancer Biology & Medicine》 SCIE CAS CSCD 2024年第9期769-783,共15页
Colorectal cancer(CRC)is the third most common cancer and the second leading cause of cancer-related deaths worldwide.Dendritic cells(DCs)constitute a heterogeneous group of antigen-presenting cells that are important... Colorectal cancer(CRC)is the third most common cancer and the second leading cause of cancer-related deaths worldwide.Dendritic cells(DCs)constitute a heterogeneous group of antigen-presenting cells that are important for initiating and regulating both innate and adaptive immune responses.As a crucial component of the immune system,DCs have a pivotal role in the pathogenesis and clinical treatment of CRC.DCs cross-present tumor-related antigens to activate T cells and trigger an antitumor immune response.However,the antitumor immune function of DCs is impaired and immune tolerance is promoted due to the presence of the tumor microenvironment.This review systematically elucidates the specific characteristics and functions of different DC subsets,as well as the role that DCs play in the immune response and tolerance within the CRC microenvironment.Moreover,how DCs contribute to the progression of CRC and potential therapies to enhance antitumor immunity on the basis of existing data are also discussed,which will provide new perspectives and approaches for immunotherapy in patients with CRC. 展开更多
关键词 Colorectal cancer dendritic cells tumor progression treatment strategies
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Tumor-derived DEFB1 induces immune tolerance by inhibiting maturation of dendritic cell and impairing CD8+T cell function in esophageal squamous cell carcinoma
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作者 Jingjing Duan Haotian Wang +10 位作者 Minglu Liu Yin Chen Ning Li Jieqiong Liu Lingxiong Wang Lin Li Yaru Liu Pengfei Dong Xiuxuan Wang Zhongyi Fan Shunchang Jiao 《Chinese Journal of Cancer Research》 SCIE CAS CSCD 2024年第4期351-367,共17页
Objective:CD8+T cells are the key effector cells in the anti-tumor immune response.The mechanism underlying the infiltration of CD8+T cells in esophageal squamous cell carcinoma(ESCC)has not been clearly elucidated.Me... Objective:CD8+T cells are the key effector cells in the anti-tumor immune response.The mechanism underlying the infiltration of CD8+T cells in esophageal squamous cell carcinoma(ESCC)has not been clearly elucidated.Methods:Fresh ESCC tissues were collected and grouped according to the infiltration density of CD8+T cells.After the transcriptome sequencing on these samples and the combined analyses with The Cancer Genome Atlas(TCGA)ESCC data,a secreted protein DEFB1 was selected to explore its potential role in the infiltration of CD8+T cells.Bioinformatics analyses,histological verification and in vitro experiments were then performed.Results:DEFB1 was highly expressed in ESCC,and the high expression of DEFB1 was an independent risk factor for overall survival.Since the up-regulation or down-regulation of DEFB1 did not affect the proliferation,migration and apoptosis of ESCC cells,we speculated that the oncogenic effect of DEFB1 was achieved by regulating microenvironmental characteristics.Bioinformatics analyses suggested that DEFB1 might play a major role in the inflammatory response and anti-tumor immune response,and correlate to the infiltration of immature dendritic cell(imDC)in ESCC.Histological analyses further confirmed that there were less CD8+T cells infiltrated,less CD83+mature DC(mDC)infiltrated and more CD1a+imDC infiltrated in those ESCC samples with high expression of DEFB1.After the treatment with recombinant DEFB1 protein,the maturation of DC was hindered significantly,followed by the impairment of the killing effects of T cells in both 2D and 3D culture in vitro.Conclusions:Tumor-derived DEFB1 can inhibit the maturation of DC and weaken the function of CD8+T cells,accounting for the immune tolerance in ESCC.The role of DEFB1 in ESCC deserves further exploration. 展开更多
关键词 CD8+T cells DEFB1 dendritic cells esophageal squamous cell carcinoma tumor immune microenvironment
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Overall clinical course of indeterminate dendritic cell tumor patients without skin lesions:A rare case report
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作者 Hao Liang Yun-Fei Zhao +1 位作者 Liu-Ping Zhang Ya-Kun Wu 《World Journal of Clinical Cases》 SCIE 2024年第19期4022-4028,共7页
BACKGROUND Indeterminate dendritic cell tumor(IDCT)is a rare tumor of immune cells,and IDCT patients without skin lesions are rarely reported.Therefore,the clinical course in this type of patient is unclear,and furthe... BACKGROUND Indeterminate dendritic cell tumor(IDCT)is a rare tumor of immune cells,and IDCT patients without skin lesions are rarely reported.Therefore,the clinical course in this type of patient is unclear,and further research on the underlying pathological mechanisms and appropriate treatments is needed.CASE SUMMARY This study describes a female IDCT patient with bile duct lesions.The strong mimicry of IDCT lesions confused doctors,and consequently,this patient,who had no skin lesions,was first diagnosed with cholangiocarcinoma.Then,she presented with persistent abdominal distension without jaundice.Enlarged mesenteric lymph nodes along with massive ascites were observed in the subsequent imaging examination.However,no tumor cells or pathogens were found in the three subsequent ascites analyses.It took 2 years to reach the correct diagnosis,which was eventually obtained by performing surgery for biopsy of the patient’s abdominal lymph nodes.However,by then,she was already in a cachexic state.Finally,she received a cycle of cyclophosphamide therapy and was advised to visit a hospital specializing in rare diseases.CONCLUSION For IDCT patients without skin lesions,early biopsy is the key to obtaining a correct diagnosis.Moreover,the collective management of IDCT patients is important.Further histological and molecular biology studies based on human specimens are critical for understanding the pathological mechanism of dendritic cell tumors in the future. 展开更多
关键词 Indeterminate dendritic cell tumor Clinical development Surgical biopsy Collective management dendritic cell Case report
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Azacitidine maintenance therapy for blastic plasmacytoid dendritic cell neoplasm allograft: A case report
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作者 Li-Li Tao Hui-Ting Wen +2 位作者 Zi-Yi Wang Juan Cheng Li Zhao 《World Journal of Clinical Cases》 SCIE 2024年第1期136-141,共6页
BACKGROUND Blastic plasmacytoid dendritic cell neoplasm(BPDCN)is a rare,highly invasive malignant neoplasm.There is no universally accepted standard of care because of its rarity and the dearth of prospective research... BACKGROUND Blastic plasmacytoid dendritic cell neoplasm(BPDCN)is a rare,highly invasive malignant neoplasm.There is no universally accepted standard of care because of its rarity and the dearth of prospective research.It is still challenging for some patients to achieve persistent clinical remission or cure,despite the success of allogeneic hematopoietic stem cell transplantation(allo-HSCT),indicating that there is still a significant recurrence rate.We report a case of prevention of BPDCN allograft recurrence by azacitidine maintenance therapy and review the relevant literature.CASE SUMMARY We report a 41-year-old man with BPDCN who was admitted to hospital due to skin sclerosis for>5 mo’duration.BPDCN was diagnosed by combined clinical assessment and laboratory examinations.Following diagnosis,the patients underwent induction consolidation chemotherapy to achieve the first complete remission,followed by bridging allo-HSCT.Post-transplantation,azacitidine(75 mg/m2 for 7 d)was administered as maintenance therapy,with repeat administration every 4–6 wk and appropriate extension of the chemotherapy cycle.After 10 cycles,the patient has been disease free for 26 mo after transplantation.Regular assessments of bone marrow morphology,minimal residual disease,full donor chimerism,Epstein–Barr virus,and cytomegalovirus all yielded normal results with no abnormalities detected.CONCLUSION Azacitidine may be a safe and effective maintenance treatment for BPDCN following transplantation because there were no overt adverse events during the course of treatment. 展开更多
关键词 Blastic plasmacytoid dendritic cell neoplasm AZACITIDINE Allogeneic hematopoietic stem cell transplantation Maintenance therapy Case report
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Blastic plasmacytoid dendritic cell neoplasm in Jinhua,China:Two case reports
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作者 Jia-Wei Cai Meng-Yao Li +3 位作者 Wei-Hao Wang Hong-Qi Shi Yi-Hui Yang Jia-Jun Chen 《World Journal of Clinical Cases》 SCIE 2024年第22期5263-5270,共8页
BACKGROUND Blastic plasmacytoid dendritic cell neoplasm(BPDCN)is a rare and clinically aggressive hematologic malignancy originating from the precursors of plasmacytoid dendritic cells.BPDCN often involves the skin,ly... BACKGROUND Blastic plasmacytoid dendritic cell neoplasm(BPDCN)is a rare and clinically aggressive hematologic malignancy originating from the precursors of plasmacytoid dendritic cells.BPDCN often involves the skin,lymph nodes,and bone marrow,with rapid clinical progression and a poor prognosis.The BPDCN diagnosis is mainly based on the immunophenotype.CASE SUMMARY In this paper,we retrospectively analyzed 2 cases of BPDCN.Both patients were elderly males.The lesions manifested as skin masses.Morphological manifestations included diffuse and dense tumor cell infiltration of the dermis and subcutaneous tissues.Immunohistochemistry staining showed that cluster of differentiation CD4,CD56,CD43,and CD123 were positive.CONCLUSION In this paper,we retrospectively analyzed 2 cases of BPDCN.Both patients were elderly males.The lesions manifested as skin masses.Morphological manifestations included diffuse and dense tumor cell infiltration of the dermis and subcutaneous tissues.Immunohistochemistry staining showed that cluster of differentiation CD4,CD56,CD43,and CD123 were positive. 展开更多
关键词 Blastic plasmacytoid dendritic cell neoplasm SKIN Clinical pathology IMMUNOPHENOTYPE Hematopoietic stem cell transplantation Case report
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Advancing the understanding and management of blastic plasmacytoid dendritic cell neoplasm:Insights from recent case studies
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作者 Yan Luo Li-Juan Wang Cheng-Long Wang 《World Journal of Clinical Cases》 SCIE 2024年第31期6441-6446,共6页
We specifically discuss the mechanisms of the pathogenesis,diagnosis,and management of blastic plasmacytoid dendritic cell neoplasm(BPDCN),a rare but aggressive haematologic malignancy characterized by frequent skin m... We specifically discuss the mechanisms of the pathogenesis,diagnosis,and management of blastic plasmacytoid dendritic cell neoplasm(BPDCN),a rare but aggressive haematologic malignancy characterized by frequent skin manifestations and systemic dissemination.The article enriches our understanding of BPDCN through detailed case reports showing the clinical,immunophenotypic,and histopathological features that are critical for diagnosing this disease.These cases highlight the essential role of pathologists in employing advanced immunophenotyping techniques to accurately identify the disease early in its course and guide treatment decisions.Furthermore,we explore the implications of these findings for management strategies,emphasizing the use of targeted therapies such as tagraxofusp and the potential of allogeneic haematopoietic stem cell transplantation in achieving remission.The editorial underscores the importance of interdisciplinary approaches in managing BPDCN,pointing towards a future where precision medicine could significantly improve patient outcomes. 展开更多
关键词 Blastic plasmacytoid dendritic cell neoplasm IMMUNOPHENOTYPING Targeted therapies Haematologic malignancy PATHOGENESIS
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3D Collagen Gels:A Promising Platform for Dendritic Cell Culture in Biomaterials Research
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作者 Kirubanandan Shanmugam 《Proceedings of Anticancer Research》 2024年第4期124-134,共11页
The three-dimensional(3D)cell culture system has garnered significant attention in recent years as a means of studying cell behavior and tissue development,as opposed to traditional two-dimensional cultures.These syst... The three-dimensional(3D)cell culture system has garnered significant attention in recent years as a means of studying cell behavior and tissue development,as opposed to traditional two-dimensional cultures.These systems can induce specific cell reactions,promote specific tissue functions,and serve as valuable tools for research in tissue engineering,regenerative medicine,and drug discovery.This paper discusses current developments in the field of three-dimensional cell culture and the potential applications of 3D type 1 collagen gels to enhance the growth and maturation of dendritic cells. 展开更多
关键词 Three-dimensional cell culture dendritic cells Type 1 collagen gels Bovine tendons and rat tails
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Effect of melt convection on primary dendrite arm spacing in directionally solidified Pb-26%Bi hypo-peritectic alloys 被引量:4
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作者 胡小武 李双明 +2 位作者 高思峰 刘林 傅恒志 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第1期65-71,共7页
Primary dendrite arm spacing(PDAS) of α phase in directionally solidified Pb-26%Bi(mass fraction) hypo-peritectic alloys was measured by considering the effect of melt convection in cylindrical samples with diffe... Primary dendrite arm spacing(PDAS) of α phase in directionally solidified Pb-26%Bi(mass fraction) hypo-peritectic alloys was measured by considering the effect of melt convection in cylindrical samples with different diameters.The experimental results show the measured PDAS increases with increasing diameter of the sample.At the growth velocity of 5 μm/s,its value changes from 161.5 μm for the sample with 1.8 mm in diameter to 240.4 μm for the sample with 7 mm in diameter.The strong melt convection in large diameter samples causes a high bulk alloy composition and a high concentration gradient in peritectic β phase,resulting in a larger PDAS.Simultaneously,the high concentration gradient could effectively promote the peritectic transformation,enhancing the dissolution of the thin α dendrite. 展开更多
关键词 Pb-26%Bi hypo-peritectic alloy primary dendrite arm spacing melt convection directional solidification
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Emerging roles of plasmacytoid dendritic cell crosstalk in tumor immunity 被引量:1
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作者 Leilei Yang Songya Li +1 位作者 Liuhui Chen Yi Zhang 《Cancer Biology & Medicine》 SCIE CAS CSCD 2023年第10期728-747,共20页
Plasmacytoid dendritic cells(pDCs)are a pioneer cell type that produces type I interferon(IFN-I)and promotes antiviral immune responses.However,they are tolerogenic and,when recruited to the tumor microenvironment(TME... Plasmacytoid dendritic cells(pDCs)are a pioneer cell type that produces type I interferon(IFN-I)and promotes antiviral immune responses.However,they are tolerogenic and,when recruited to the tumor microenvironment(TME),play complex roles that have long been a research focus.The interactions between p DCs and other components of the TME,whether direct or indirect,can either promote or hinder tumor development;consequently,p DCs are an intriguing target for therapeutic intervention.This review provides a comprehensive overview of p DC crosstalk in the TME,including crosstalk with various cell types,biochemical factors,and microorganisms.An in-depth understanding of p DC crosstalk in TME should facilitate the development of novel p DC-based therapeutic methods. 展开更多
关键词 Plasmacytoid dendritic cell tumor microenvironment cell crosstalk immune activation immune suppression
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Study on mechanism of increased allergenicity induced by Ara h 3 from roasted peanut using bone marrow-derived dendritic cells 被引量:1
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作者 Minjia Wang Shuo Wang +3 位作者 Xiaodong Sun Zhirui Deng Bing Niu Qin Chen 《Food Science and Human Wellness》 SCIE CSCD 2023年第3期755-764,共10页
Little information was so far available about allergenic mechanism of the roasted peanut allergens during initial stages of allergy.The purpose of this study was to determine the influence of roasting(150℃,20 min)on ... Little information was so far available about allergenic mechanism of the roasted peanut allergens during initial stages of allergy.The purpose of this study was to determine the influence of roasting(150℃,20 min)on biochemical and biological properties of Ara h 3,a major peanut allergen.Allergenicity of roasted peanut emulsion to mice,differences in uptakes between Ara h 3 purified from raw peanuts(named as Ara h 3-Raw)and that purified from roasted peanuts(named as Ara h 3-Roasted)by bone marrow-derived dendritic cells(BMDCs)and the implication of cell surface receptors involving in uptake,and changes in glycosylation and structure of Ara h 3 after roasting were analyzed in this study.This study suggested that roasting increased allergenicity of peanut to BALB/c mice.Maillard reaction and structural changes of Ara h 3 induced by roasting significantly altered the uptake of Ara h 3-Roasted by BMDCs,and modified Ara h 3 fate in processes involved in immunogenicity and hyper allergenicity,indicating that food processing pattern can change food allergenicity. 展开更多
关键词 Roasted peanut Ara h 3 Bone marrow-derived dendritic cells(BMDCs) ALLERGENICITY Maillard reactions
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Effect of cooling rates on dendrite spacings of directionally solidified DZ125 alloy under high thermal gradient 被引量:11
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作者 ZHANG Weiguo LIU Lin ZHAO Xinbao HUANG Taiwen YU Zhuhuan QU Min FU Hengzhi 《Rare Metals》 SCIE EI CAS CSCD 2009年第6期633-638,共6页
The dendrite morphologies and spacings of directionally solidified DZ125 superalloy were investigated under high thermal gradient about 500 K/cm. The results reveal that, with increasing cooling rate, both the spacing... The dendrite morphologies and spacings of directionally solidified DZ125 superalloy were investigated under high thermal gradient about 500 K/cm. The results reveal that, with increasing cooling rate, both the spacings of primary and secondary dendrite arms decrease, and the dendrite morphologies transit from coarse to superfme dendrite. The secondary dendrite arms trend to be refined and be well developed, and the tertiary dendrite will occur. The predictions of the Kurz/Fisher model and the Hunt/Lu model accord basically with the experimental data for primary dendrite arm spacing. The regression equation of the primary dendrite arm spacings 21 and the cooling rate Vc is λ1 = 0.013 Vc^-0.32. The regression equation of the secondary dendrite arm spacing λ2 and the cooling rate Vc is λ2 = 0.00258 Vc^-0.31, which gives good agreement with the Feurer/Wunderlin model. 展开更多
关键词 directional solidification superalloy thermal gradient cooling rate dendrite arm spacing
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Mechanism of reduction of columnar dendrite spacing in unidirectional solidification caused by electric current passing through solid liquid interface 被引量:5
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作者 常国威 袁军平 +3 位作者 王自东 吴春京 王新华 胡汉起 《中国有色金属学会会刊:英文版》 CSCD 2000年第5期610-613,共4页
Considering the S L interface morphology stability, the S L interface energy, the Joule heat produced by electric current at the S L interface, and the change of solute concentration at the S L interface indirectly ca... Considering the S L interface morphology stability, the S L interface energy, the Joule heat produced by electric current at the S L interface, and the change of solute concentration at the S L interface indirectly caused by electric current, the mechanism of reduction of columnar dendrite spacing in unidirectional solidification caused by electric current passing through solid liquid interface was studied. The following conclusions can be drawn that: 1) under sub rapid solidification condition, increasing electric current density will improve the stability of S L interface, thus decreasing the columnar dendrite spacing; 2)there are two ways by which the increase of electric current decreases the columnar dendrite spacing, one is promoting the splitting of the protruding tips at the S L interface, the other is promoting the forming of new convex parts at the bottom of the concave interface.[ 展开更多
关键词 Cu Al alloy UNIDIRECTIONAL solidification COLUMNAR dendrite spacing MECHANISM of current effect
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Reduction in secondary dendrite arm spacing in cast eutectic Al–Si piston alloys by cerium addition 被引量:3
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作者 R.Ahmad M.B.A.Asmael +1 位作者 N.R.Shahizan S.Gandouz 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2017年第1期91-101,共11页
The effects of Ce on the secondary dendrite arm spacing(SDAS) and mechanical behavior of Al-Si-Cu-Mg alloys were investigated. The reduction of SDAS at different Ce concentrations was evaluated in a directional soli... The effects of Ce on the secondary dendrite arm spacing(SDAS) and mechanical behavior of Al-Si-Cu-Mg alloys were investigated. The reduction of SDAS at different Ce concentrations was evaluated in a directional solidification experiment via computer-aided cooling curve thermal analysis(CA-CCTA). The results showed that 0.1wt%-1.0wt% Ce addition resulted in a rapid solidification time, ?ts, and low solidification temperature, ?T_S, whereas 0.1wt% Ce resulted in a fast solidification time, Δ^(ta-Al), of the α-Al phase. Furthermore, Ce addition refined the SDAS, which was reduced to approximately 36%. The mechanical properties of the alloys with and without Ce were investigated using tensile and hardness tests. The quality index(Q) and ultimate tensile strength of(UTS) Al-Si-Cu-Mg alloys significantly improved with the addition of 0.1wt% Ce. Moreover, the base alloy hardness was improved with increasing Ce concentration. 展开更多
关键词 eutectic alloys aluminum silicon alloys CERIUM microstructure dendriteS spacing mechanical properties
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Effect of sample diameter on primary and secondary dendrite arm spacings during directional solidification of Pb-26wt.%Bi hypo-peritectic alloy 被引量:2
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作者 HU Xiaowu YAN Hong +2 位作者 CHEN Wenjing LI Shuangming FU Hengzhi 《Rare Metals》 SCIE EI CAS CSCD 2011年第4期424-431,共8页
The microstructure scales of dendrites, such as primary and secondary dendrite arm spacings, control the segregation profiles and the formation of secondary phases within interdendritic regions, which determine the pr... The microstructure scales of dendrites, such as primary and secondary dendrite arm spacings, control the segregation profiles and the formation of secondary phases within interdendritic regions, which determine the properties of solidified structures. Investigations on primary and secondary dendrite arm spacings of primary a-phase during directionally solidified Pb-26wt%Bi hypo-peritectic alloy were carried out in this research, and systematic studies were conducted using cylindrical samples with different diameters (Ф = 1.8 and 7.0 mm) in order to analyze the effects of sample diameter on the primary and secondary dendrite arm spacings. In this work, the dependence of dendrite arm spacings on growth velocity was established. In addition, the experimental data concerning the primary and secondary dendrite ann spacings were compared with the main predictive dendritic models from the literatures. A comparison between experimental results for dendrite arm spacings of the 1.8-mm-diameter sample and 7.0-ram-diameter sample was also conducted. 展开更多
关键词 lead bismuth alloys dendrite arm spacing directional solidification dendriteS
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Structural changes in pyramidal cell dendrites and synapses in the unaffected side of the sensorimotor cortex following transcranial magnetic stimulation and rehabilitation training in a rat model of focal cerebral infarct 被引量:2
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作者 Chuanyu Liu Surong Zhou +3 位作者 Xuwen Sun Zhuli Liu Hongliang Wu Yuanwu Mei 《Neural Regeneration Research》 SCIE CAS CSCD 2011年第9期676-680,共5页
Very little is known about the effects of transcranial magnetic stimulation and rehabilitation training on pyramidal cell dendrites and synapses of the contralateral, unaffected sensorimotor cortex in a rat model of f... Very little is known about the effects of transcranial magnetic stimulation and rehabilitation training on pyramidal cell dendrites and synapses of the contralateral, unaffected sensorimotor cortex in a rat model of focal cerebral infarct. The present study was designed to explore the mechanisms underlying improved motor function via transcranial magnetic stimulation and rehabilitation training following cerebral infarction. Results showed that rehabilitation training or transcranial magnetic stimulation alone reduced neurological impairment in rats following cerebral infarction, as well as significantly increased synaptic curvatures and post-synaptic density in the non-injured cerebral hemisphere sensorimotor cortex and narrowed the synapse cleft width. In addition, the percentage of perforated synapses increased. The combination of transcranial magnetic stimulation and rehabilitation resulted in significantly increased total dendritic length, dendritic branching points, and dendritic density in layer V pyramidal cells of the non-injured cerebral hemisphere motor cortex. These results demonstrated that transcranial magnetic stimulation and rehabilitation training altered structural parameters of pyramidal cell dendrites and synapses in the non-injured cerebral hemisphere sensorimotor cortex, thereby improving the ability to compensate for neurological functions in rats following cerebral infarction. 展开更多
关键词 cerebral infarction transcranial magnetic stimulation rehabilitation training sensorimotor cortex pyramidal cell dendrites SYNAPSE neural regeneration
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Dendrite Spacing Selection during Directional Solidification of Pivalic Acid-Ethanol System 被引量:1
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作者 Myung-Jin Suk Young-Min Park Youn-Che Kim 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2008年第3期340-342,共3页
Unidirectional solidification of pivalic acid (PVA)-ethanol (Eth) mixture was performed to examine whether an allowable range of primary dendrite spacing definitely exists at a given growth velocity and how the ra... Unidirectional solidification of pivalic acid (PVA)-ethanol (Eth) mixture was performed to examine whether an allowable range of primary dendrite spacing definitely exists at a given growth velocity and how the range is history-dependent. PVA-0.59 wt pct Eth was unidirectionally solidified in the range of growth velocity 0.5-64 μm/s at the temperature gradient of 2.3 K/ram. Sequential change in growth velocity was imposed to determine the upper and lower limits for the allowable range of stable spacing. An allowable range of the steady state primary spacing was observed at a given growth velocity, and the extent of the range seems to be dependent on the degree to which step-increase or step-decrease in growth velocity is accomplished. As the degree of sequential change in growth velocity increases, the history-dependence of the selection for the primary dendrite spacing tends to disappear. 展开更多
关键词 dendrite spacing History-dependent spacing selection Pivalic acid-ethanol
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Influence of directional solidification variables on primary dendrite arm spacing of Ni-based superalloy DZ125 被引量:3
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作者 Zhang Weiguo Liu Lin +4 位作者 Huang Taiwen Zhao Xinbao Qu Min Yu Zhuhuan Fu Hengzhi 《China Foundry》 SCIE CAS 2009年第4期300-304,共5页
The primary dendrite morphology and spacing of DZ125 superalloy have been observed during directional solidification under high thermal gradient about 500 K/cm. The results reveal that the primary dendrite arm spacing... The primary dendrite morphology and spacing of DZ125 superalloy have been observed during directional solidification under high thermal gradient about 500 K/cm. The results reveal that the primary dendrite arm spacing decreases from 94 μm to 35.8 μm with the increase of directional solidification cooling rate from 2.525 K/s to 36.4 K/s. The regression equation of the primary dendrite arm spacings A, versus cooling rate is λ1=0.013(GV)-0.32. The predictions of Kurz/Fisher model and Hunt/Lu model accord reasonably well with the experimental data. The influence of directional solidification rate under variable thermal gradient on the primary dendrite arm spacing has also been investigated. 展开更多
关键词 directional solidification thermal gradient cooling rate primary dendrite arm spacing SUPERALLOY
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