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Myocardial metastasis from ZEB1-and TWIST-positive spindle cell carcinoma of the esophagus:A case report
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作者 Yoshihiro Shibata Hirofumi Ohmura +4 位作者 Kazuki Komatsu Kosuke Sagara Atsuji Matsuyama Ryuji Nakano Eishi Baba 《World Journal of Gastroenterology》 SCIE CAS 2024年第11期1636-1643,共8页
BACKGROUND Metastatic cardiac tumors are known to occur more frequently than primary cardiac tumors,however,they often remain asymptomatic and are commonly dis-covered on autopsy.Malignant tumors with a relatively hig... BACKGROUND Metastatic cardiac tumors are known to occur more frequently than primary cardiac tumors,however,they often remain asymptomatic and are commonly dis-covered on autopsy.Malignant tumors with a relatively high frequency of cardiac metastasis include mesothelioma,melanoma,lung cancer,and breast cancer,whereas reports of esophageal cancer with cardiac metastasis are rare.CASE SUMMARY The case of a 60-year-old man who complained of dysphagia is presented.Upper gastrointestinal endoscopy showed a submucosal tumor-like elevated lesion in the esophagus causing stenosis.Contrast-enhanced computed tomography showed left atrial compression due to the esophageal tumor,multiple liver and lung metastases,and a left pleural effusion.Pathological examination of a biopsy speci-men from the esophageal tumor showed spindle-shaped cells,raising suspicion of esophageal sarcoma.The disease progressed rapidly,and systemic chemotherapy was deemed necessary,however,due to his poor general condition,adminis-tration of cytotoxic agents was considered difficult.Given his high Combined Positive Score,nivolumab was administered,however,the patient soon died from the disease.The autopsy confirmed spindle cell carcinoma(SCC)of the esophagus and cardiac metastasis with similar histological features.Cancer stem cell markers,ZEB1 and TWIST,were positive in both the primary tumor and the cardiac metastasis.CONCLUSION To the best of our knowledge,there have been no prior reports of cardiac metastasis of esophageal SCC.This case highlights our experience with a patient with esophageal SCC who progressed rapidly and died from the disease,with the autopsy examination showing cardiac metastasis. 展开更多
关键词 Spindle cell carcinoma ESOPHAGUS Myocardial metastasis Epithelial-mesenchymal transition Case report
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Growth‑Controllable Spindle Chain Heterostructural Anodes Based on MIL‑88A for Enhanced Lithium/Sodium Storage
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作者 Zhiwen Long Han Dai +4 位作者 Caiqin Wu Zhengchun Li Hui Qiao Keliang Wang Qufu Wei 《Advanced Fiber Materials》 SCIE EI CAS 2024年第1期297-311,共15页
Engineering bead-on-string architectures with refined interfacial interactions and low ion diffusion barriers is a highly promising but challenging approach for lithium/sodium storage.Herein,a spindle-chain-structured... Engineering bead-on-string architectures with refined interfacial interactions and low ion diffusion barriers is a highly promising but challenging approach for lithium/sodium storage.Herein,a spindle-chain-structured Fe-based metal organic frameworks(MIL-88A)self-sacrificial template was constructed via the seed-mediated growth of Fe^(3+)and fumaric acid in an aqueous solution,which is an environmentally friendly synthesis route.The seed-mediated growth method effectively segregates the nucleation stage from the subsequent growth phase,offering precise control over the growth patterns of MIL-88A through manipulation of kinetic and thermodynamic parameters.The structural diversity,fast ion/electron diffusion,and unique interfaces of whole anodes are simultaneously enhanced through optimization of the spindle-chain structure of Fe_(2)O_(3)@N-doped carbon nanofibers(FO@NCNFs)at the atomic,nano,and macroscopic levels.Benefiting from their heteroatom-doping conductive networks,porous structure,and synergistic effects,FO@NCNFs exhibit a remarkable rate performance of 167 mAh g^(-1)at 10 A g^(-1)after 2000 cycles for lithium-ion batteries(LIBs)and long-term cycling stability with a sustained capacity of 260 mAh g^(-1)at 2 A g^(-1)after 2000 cycles for sodium-ion batteries(SIBs).This versatile approach for fabricating bead-on-string architectures at both the nanoscale and macroscale is promising for the development of high-energy-density and high-power-density electrode materials. 展开更多
关键词 Spindle chain heterostructure Seed-mediated growth Multi-level optimization Metal-organic frameworks Lithium/sodium storage
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Pleomorphic leiomyosarcoma of the maxilla with metastasis to the colon:A case report
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作者 Asma Alnajjar Abdulrahman Alfadda +3 位作者 Abdullah Mohammad Alqaraawi Bader Alajlan Jean Paul Atallah Hussah Fahad AlHussaini 《World Journal of Gastrointestinal Endoscopy》 2024年第6期361-367,共7页
BACKGROUND Pleomorphic leiomyosarcomas make up around 8.6%of all leiomyosarcomas.They behave aggressively and often have poor prognoses.They can affect the gastrointestinal tract and retroperitoneum.To date,pleomorphi... BACKGROUND Pleomorphic leiomyosarcomas make up around 8.6%of all leiomyosarcomas.They behave aggressively and often have poor prognoses.They can affect the gastrointestinal tract and retroperitoneum.To date,pleomorphic leiomyosarcoma involving the mesocolon have been reported in nine patients.CASE SUMMARY The patient was a 44-year-old man with a history of pleomorphic leiomyosarcoma of the left maxilla with metastasis to the lung and liver.His most recent positron emission tomography-computed tomography(PET-CT)scan showed uptake in the ascending and transverse colons.A colonoscopy revealed a 5.0 cm×3.5 cm×3.0 cm pedunculated polyp in the ascending colon.The polyp was removed using hot snare polypectomy technique and retrieved with Rothnet.Histopathologic examination of the polyp showed a metastatic pleomorphic leiomyosarcoma.CONCLUSION Uptake(s)on PET-CT in a patient with pleomorphic leiomyosarcoma should raise suspicion for metastasis. 展开更多
关键词 Pleomorphic leiomyosarcoma Colon polyp Hot snare polypectomy Maxillary Spindle cell tumor Case report
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Spindle-view系统在猪卵母细胞去核中的应用 被引量:8
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作者 杨宇 戴建军 +4 位作者 张廷宇 吴华莉 陈学进 张德福 马恒东 《生物工程学报》 CAS CSCD 北大核心 2007年第6期1140-1145,共6页
应用Spindle—view对体外成熟培养36、42、44和45h的猪体外成熟卵母细胞减数分裂纺锤体进行去核操作,并与传统去核方法(McGrath—Solter去核法,挤压去核法)相比较,结果表明:①在42~48h之间利用Spindle—view得到的猪卵纺锤体影... 应用Spindle—view对体外成熟培养36、42、44和45h的猪体外成熟卵母细胞减数分裂纺锤体进行去核操作,并与传统去核方法(McGrath—Solter去核法,挤压去核法)相比较,结果表明:①在42~48h之间利用Spindle—view得到的猪卵纺锤体影像与极体的相对位置没有明显的变化;②Spindle—view适合用于猪体外成熟卵母细胞减数分裂纺锤体的观察及去核;去核效率与其他两种方法相比差异极显著(95.5%,42.1%,74.2%,P〈0.01);③纺锤体成像是否清晰可用于猪卵母细胞的质量监控。 展开更多
关键词 Spindle—view 猪卵母细胞 去核 减数分裂纺锤体
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Localization of stationary pronuclei during conjugation of Paramecium as indicated by immunofluorescence staining 被引量:2
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作者 高欣 朱嘉骏 +3 位作者 杨仙玉 袁进强 王逸雯 宋敏国 《Zoological Research》 CAS CSCD 北大核心 2011年第4期461-464,共4页
After the third prezygotic division during conjugation of Paramecium caudatum,migratory and stationary pronuclei are produced.The migratory pronuclei remain in the paroral region tightly against the conjugating bounda... After the third prezygotic division during conjugation of Paramecium caudatum,migratory and stationary pronuclei are produced.The migratory pronuclei remain in the paroral region tightly against the conjugating boundaries;while the stationary pronuclei are located beside the migratory pronuclei.To date,however,it is not clear what causes this close side-by-side localization between migratory and stationary pronuclei.In the current study,immunofluorescence staining with monoclonal antibody of anti-α tubulin indicated that "U" or "V" shaped spindles connected the migratory and stationary pronuclei during the third prezygotic division.This observation accounts for the close localization between these two types of pronuclei. 展开更多
关键词 PARAMECIUM CONJUGATION Connecting spindles PRONUCLEUS
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New details indicated by different stainings during conjugation of ciliated protozoa Paramecium 被引量:2
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作者 高欣 杨仙玉 +3 位作者 朱嘉骏 袁进强 王逸雯 宋敏国 《Zoological Research》 CAS CSCD 北大核心 2011年第6期651-656,共6页
During conjugation of Paramecium caudatum, nuclear events occur in a scheduled program. Morphological studies on nuclear behavior during conjugation of P. caudatum have been performed since the end of the 19th century... During conjugation of Paramecium caudatum, nuclear events occur in a scheduled program. Morphological studies on nuclear behavior during conjugation of P. caudatum have been performed since the end of the 19th century. Here we report on new details concerning the conjugation of P. caudatum through the staining of conjugating ceils with protargol, carbol fuchsin solution, Hoechst 33342 and immunofluorescence labeling with monoclonal antibody of anti-a tubulin. 1) The crescent nucleus is a characteristic of the meiotic prophase of P. caudatum, has an unstained area. We stained this area with protargol, which was separated from the chromatin area and was not detected by the other stainings. 2) In regards to the four meiotic products, it has long been considered that only one product enters the paroral cone region (PC) and survives after meiosis. However, our protargol and immunofluorescence labeling results indicated that PC entrance of the meiotic product happened before the completion of meiosis instead of after. 3) In our previous study, protargol staining indicated the presence of a swollen structure around the central part of the "U" and "V" shaped spindles connecting the two types of prospective pronuclei. However, immunofluorescence labeling with anti-a tubulin antibodies gave a different image from protargol. All these observations form the basis for further studies of their molecular mechanisms. 展开更多
关键词 PARAMECIUM CONJUGATION CRESCENT PC entrance Connecting spindles
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水牛卵母细胞去核方法的摸索 被引量:9
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作者 杨素芳 石德顺 +1 位作者 韦精卫 陆凤花 《草食家畜》 2003年第4期19-22,共4页
本研究对水牛卵母细胞的去核方法进行了摸索。首先通过盲吸法去核,摸索水牛卵母细胞在体外成熟不同时间的成熟率和去核率;其次采用spindle-View系统去核,摸索用这种系统去核的最佳时间。水牛卵母细胞IVM16-18h与IVM 19-21h的成熟率之间... 本研究对水牛卵母细胞的去核方法进行了摸索。首先通过盲吸法去核,摸索水牛卵母细胞在体外成熟不同时间的成熟率和去核率;其次采用spindle-View系统去核,摸索用这种系统去核的最佳时间。水牛卵母细胞IVM16-18h与IVM 19-21h的成熟率之间有显著差别(43.0%vs58.2%,P<0.05),与22-24h组的成熟率之间有极显著差别(43.0%vs 68.8%,P<0.01).而去核率的情况刚好相反。随着卵母细胞成熟时间的延长,卵细胞的核与PB1的相对距离增大。在体外成熟18h,20h,22h,有较大比例(分别为72.6%、67.9%、64.0%)的卵母细胞中的核与PB1的位置较近,但当成熟时间增加到24h时,这一比例下降到57.6%(72.6%vs 57.6%,P<0.05),如采用Spindle-View系统去核则可消除成熟时间对去核率的影响,这些结果表明:1.水牛卵母细胞的成熟时间的延长不断提高,而去核率呈下降趋势;2.水牛卵母细胞成熟时间的延长会增加核与PB1的相对距离;利用Spindle-View系统可提高成熟时间较长的卵母细胞的去核率。 展开更多
关键词 水牛 卵母细胞 去核方法 盲吸法 成熟率 去核率 Spindle—View系统 细胞核移植 克隆
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AUTOMATIC CONTROL OF REGENERATIVE CUTTING CHATTER BASED ON OPTIMAL REGULATION OF SPINDLE SPEED
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作者 付连宇 石红雁 +1 位作者 鲍明 于骏一 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2000年第1期59-63,共5页
An applicable method to control regenerative cutting chatter automatically based on the optimal regulation of spindle speed is introduced. The optimal value of the phase shift angle of the regenerative chatter signal ... An applicable method to control regenerative cutting chatter automatically based on the optimal regulation of spindle speed is introduced. The optimal value of the phase shift angle of the regenerative chatter signal between the two successive cuts is 270°. The cutting process can be adjusted from the unstable region to stable one whenever regenerative chatter occurs if the phase shift angle is kept 270° by the optimal regulation of spindle speed. The theoretical analysis and the experimental results prove that the optimal regulation of spindle speed can effectively control regenerative cutting chatter. In addition, a reliablelly optimal control system of reliable spindle speed is presented. There is no need for system identification of the machine tool, and it is easy to put this regenerative chatter control method into practice, so the method has excellent application prospect. 展开更多
关键词 CUTTING regenerative chatter phase shift angle spindle speed
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Analysis on Apple Tree Structures by Free Spindle Pruning Mode
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作者 郝婕 索相敏 +3 位作者 李学营 王献革 鄢新民 冯建忠 《Agricultural Science & Technology》 CAS 2016年第10期2238-2241,共4页
To determine the correlation between the stem taperingness and central shaft by free spindle pruning mode on different apple cultivars, the central shaft growth data of three cultivars of free spindle short shoot "F... To determine the correlation between the stem taperingness and central shaft by free spindle pruning mode on different apple cultivars, the central shaft growth data of three cultivars of free spindle short shoot "Fuji", free spindle long shoot "Fuji", free spindle "Huaguan" were investigated in Xingtang County of Hebei Province by SPSS analysis. The results showed that the stem taperingness on free spindle short shoot "Fuji" was in negative correlation with central shaft, but the correlation was not significant. While the stem taperingness on free spindle long shoot "Fuji" was in positive correlation with central shaft, but the correlation was not significant either. The stern taperingness on free spindle "Huaguan" was in negative correlation with central shaft, and the correlation between the stem taperingness and the central shaft total length was significant at the level of 0.01. The results.provided scientific theoretical basis for guiding the dwarfing rootstocks close planting apple tree pruning technology. 展开更多
关键词 APPLE Free spindle pruning mode Structure analysis
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Research on the Dynamic Model of Spindle Rotation Induced Error Compensation System of Boring and its Simulation
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作者 杜正春 李春梅 颜景平 《Journal of Southeast University(English Edition)》 EI CAS 1999年第2期92-97,共6页
In this paper we address the dynamics of compensation cutting process from both Laplace s frequency domain and the time domain of the first time, using the two computer aided analyzing softwares: MATLAB and SIMULI... In this paper we address the dynamics of compensation cutting process from both Laplace s frequency domain and the time domain of the first time, using the two computer aided analyzing softwares: MATLAB and SIMULINK. Theoretical analysis and simulation experiments firstly show that not only the systematical stiffness of workpiece, spindle and tools, but also the regenerated coefficient affects the compensation displacement effect. The results show that the SREC is practicable in reality to decease the spindle induced errors in many engineering applications such as hard boring through simulation and the preliminary experiment results. 展开更多
关键词 spindle rotation induced error compensation (SREC) dynamic simulation regenerated coefficient μ boring process
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高速立式加工中心主轴箱结构分析及优化
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作者 陆君 文怀兴 吕玉清 《机械设计与制造》 北大核心 2010年第12期168-169,共2页
以高速立式加工中心主轴箱为研究对象,为满足高速加工中心整体性能的需要,利用pro/E软件,建立了四种主轴箱结构的三维模型,分别进行了主轴箱的力学分析和静刚度计算,并对最优设计方案进行了合理的结构优化。在满足主轴箱刚度的前提下,... 以高速立式加工中心主轴箱为研究对象,为满足高速加工中心整体性能的需要,利用pro/E软件,建立了四种主轴箱结构的三维模型,分别进行了主轴箱的力学分析和静刚度计算,并对最优设计方案进行了合理的结构优化。在满足主轴箱刚度的前提下,减少了重量,降低了成本。为主轴箱动态性能的分析研究奠定了基础,为提高机床性能提供理论依据。 展开更多
关键词 高速加工中心 立式加工中心 主轴箱 结构分析 结构优化 SPINDLE box center high speed analysis 最优设计方案 整体性能 PRO/E软件 轴箱结构 研究对象 三维模型 力学分析 理论依据 刚度计算 分析研究 动态性能
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关于技术英语写作中的同位语运用
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作者 徐大伟 《语言教育》 2002年第6期41-42,共2页
众所周知,技术英语写作中频繁运用同位语的主要原因之一是同位语能直接对它前面的名词或代词作进一步的描述、解释或说明。然而,如何正确运用同位语以及如何正确选择其表达中心乃是同位语能否起到恰如其分的描述和解释作用的关键。本文... 众所周知,技术英语写作中频繁运用同位语的主要原因之一是同位语能直接对它前面的名词或代词作进一步的描述、解释或说明。然而,如何正确运用同位语以及如何正确选择其表达中心乃是同位语能否起到恰如其分的描述和解释作用的关键。本文举两个汉译英的实例来说明技术英语写作中某些同位语的运用方法。例1 我们公司设计及制造的这台专用机床具有体积小、重量轻、加工精度高及耗电少等特点。通常情况下,例1可译成: 展开更多
关键词 解释作用 动名词短语 专用机床 加工精度 文举 机床主轴 辅助成分 simplified SPINDLE 通讯地址
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基于ANSYS有限元法的某型车床主轴振动频率响应分析(英文) 被引量:1
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作者 周泽新 《机床与液压》 北大核心 2015年第18期57-63,69,共8页
以机械加工中常用车床CA6140为研究对象,分别采用基于ANSYS的有限元法和实验法对其主轴进行了振动模态与频率响应分析,并对两者的计算结果进行了对比分析,验证了ANSYS数值仿真的准确性。数值仿真和实验结果表明:主轴在一阶频率和五阶频... 以机械加工中常用车床CA6140为研究对象,分别采用基于ANSYS的有限元法和实验法对其主轴进行了振动模态与频率响应分析,并对两者的计算结果进行了对比分析,验证了ANSYS数值仿真的准确性。数值仿真和实验结果表明:主轴在一阶频率和五阶频率处容易发生共振,但未达到共振,且低阶频率要比高阶频率对主轴的振动影响大;通过实验得出,主轴在工作状态下的最大振动主要集中在其两端轴承附近区域,因此改进轴承是减小主轴振动、保证主轴加工精度的重要途径,其研究结果可对车床的结构优化设计提供理论指导。 展开更多
关键词 ANSYS FEM LATHE SPINDLE MODAL ANALYSIS HARMONIC response ANALYSIS Resonance
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Deficit of mitochondria-derived ATP during oxidative stress impairs mouse MII oocyte spindles 被引量:25
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作者 Xiao Zhang Xue Qing Wu +2 位作者 Shuang Lu Ying Lu Guo Xu Ma 《Cell Research》 SCIE CAS CSCD 2006年第10期841-850,共10页
Although the role of oxidative stress in maternal aging and infertility has been suggested, the underlying mechanisms are not fully understood. The present study is designed to determine the relationship between mitoc... Although the role of oxidative stress in maternal aging and infertility has been suggested, the underlying mechanisms are not fully understood. The present study is designed to determine the relationship between mitochondrial function and spindle stability in metaphase II (MII) oocytes under oxidative stress. MII mouse oocytes were treated with H2O2 in the presence or absence of permeability transition pores (PTPs) blockers cyclosporin A (CsA). In addition, antioxidant N-acetylcysteine (NAC), F0/F1 synthase inhibitor oligomycin A, the mitochondria uncoupler carbonyl cyanide 4-trifluoro- methoxyphenylhydrazone (FCCP) or thapsigargin plus 2.5 mM Ca^2+ (Th+2.5 mM Ca^2+) were used in mechanistic studies. Morphologic analyses of oocyte spindles and chromosomes were performed and mitochondrial membrane potential (AWm), cytoplasmic free calcium concentration ([Ca^2+]c) and cytoplasmic ATP content within oocytes were also assayed. In a time- and H202 dose-dependent manner, disruption of meiotic spindles was found after oocytes were treated with H202, which was prevented by pre-treatment with NAC. Administration of H2O2 led to a dissipation of AWm, an increase in [Ca^2+]c and a decrease in cytoplasmic ATP levels. These detrimental responses of oocytes to H2O2 treatment could be blocked by pre-incubation with CsA. Similar to H2O2, both oligomycin A and FCCP dissipated AWm, decreased cytoplasmic ATP contents and disassembled MII oocyte spindles, while high [Ca^2+]c alone had no effects on spindle morphology. In conclusion, the decrease in mitochondria-derived ATP during oxidative stress may cause a disassembly of mouse MII oocyte spindles, presumably due to the opening of the mitochondrial PTPs. 展开更多
关键词 spindle oxidative stress mitochondria permeability transition pore ATP
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Surgical outcome of carcinosarcoma of the gall bladder:A review 被引量:13
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作者 Takehiro Okabayashi Zhao-Li Sun +1 位作者 Robert A Montgomery Kazuhiro Hanazaki 《World Journal of Gastroenterology》 SCIE CAS CSCD 2009年第39期4877-4882,共6页
Carcinosarcoma,which comprises less than one percent of all gall bladder neoplasms,is characterized by the presence of variable proportions of carcinomatous and sarcomatous elements.Recently,several reports have descr... Carcinosarcoma,which comprises less than one percent of all gall bladder neoplasms,is characterized by the presence of variable proportions of carcinomatous and sarcomatous elements.Recently,several reports have described patients suffering from carcinosarcoma of the gall bladder.However,there are no large studies regarding the clinicopathologic features,therapeutic management,and surgical outcome of this disease because the number of patients who undergo resection of gall bladder carcinosarcoma at a single institution is limited.A Medline search was performed using the keywords 'gall bladder' and 'carcinosarcoma'.Additional articles were obtained from references within the papers identified by the Medline search.Optimal adjuvant chemotherapy and/or radiotherapy protocols for carcinosarcoma of the gall bladder have not been established.Curative surgical resection offers the only chance for long-term survival from this disease.The outcome of 36 patients who underwent surgical resection for carcinosarcoma of the gall bladder was poor;the 3-year overall survival rate was only 31.0% and the median survival time was 7.0 mo.Since the postoperative prognosis of carcinosarcoma of the gall bladder is worse than that of adenocarcinoma,new adjuvant chemotherapies and/or radiation techniques are essential for improvement of surgical outcome. 展开更多
关键词 Gall bladder CARCINOSARCOMA Spindle cell carcinoma SURGERY OUTCOME
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Compliance Analysis of a 3-DOF Spindle Head by Considering Gravitational Effects 被引量:11
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作者 LI Qi WANG Manxin +1 位作者 HUANG Tian CHETWYND G Derek 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2015年第1期1-10,共10页
The compliance modeling is one of the most significant issues in the stage of preliminary design for parallel kinematic machine(PKM). The gravity ignored in traditional compliance analysis has a significant effect o... The compliance modeling is one of the most significant issues in the stage of preliminary design for parallel kinematic machine(PKM). The gravity ignored in traditional compliance analysis has a significant effect on pose accuracy of tool center point(TCP) when a PKM is horizontally placed. By taking gravity into account, this paper presents a semi-analytical approach for compliance analysis of a 3-DOF spindle head named the A3 head. The architecture behind the A3 head is a 3-RPS parallel mechanism having one translational and two rotational movement capabilities, which can be employed to form the main body of a 5-DOF hybrid kinematic machine especially designed for high-speed machining of large aircraft components. The force analysis is carried out by considering both the externally applied wrench imposed upon the platform as well as gravity of all moving components. Then, the deflection analysis is investigated to establish the relationship between the deflection twist and compliances of all joints and links using semi-analytical method. The merits of this approach lie in that platform deflection twist throughout the entire task workspace can be evaluated in a very efficient manner. The effectiveness of the proposed approach is verified by the FEA and experiment at different configurations and the results show that the discrepancy of the compliances is less than 0.04 μm/N^-1 and that of the deformations is less than 10μm. The computational and experimental results show that the deflection twist induced by gravity forces of the moving components has significant bearings on pose accuracy of the platform, providing an informative guidance for the improvement of the current design. The proposed approach can be easily applied to the compliance analysis of PKM by considering gravitational effects and to evaluate the deformation caused by gravity throughout the entire workspace. 展开更多
关键词 compliance modeling GRAVITY spindle head
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Sensory reinnervation of muscle spindles after repair of tibial nerve defects using autogenous vein grafts 被引量:8
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作者 Youwang Pang Qingnan Hong Jinan Zheng 《Neural Regeneration Research》 SCIE CAS CSCD 2014年第6期610-615,共6页
Motor reinnervation after repair of tibial nerve defects using autologous vein grafts in rats has previously been reported, but sensory reinnervation after the same repair has not been fully investigated. In this stud... Motor reinnervation after repair of tibial nerve defects using autologous vein grafts in rats has previously been reported, but sensory reinnervation after the same repair has not been fully investigated. In this study, partial sensory reinnervation of muscle spindles was observed after repair of lO-mm left tibial nerve defects using autologous vein grafts with end-to-end anasto- mosis in rats, and functional recovery was confirmed by electrophysiological studies. There were no significant differences in the number, size, or electrophysiological function of reinnervated muscle spindles between the two experimental groups. These findings suggest that repair of short nerve defects with autologous vein grafts provides comparable results to immediate end-to-end anastomosis in terms of sensory reinnervation of muscle spindles. 展开更多
关键词 nerve regeneration peripheral nerve injury muscle spindle VEIN tibial nerve gastroc-nemius muscle nearofilament protein H neural regeneration
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Lightweight design of 45000r/min spindle using full factorial design and extreme vertices design methods 被引量:7
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作者 PARK Seong-jin LEE Choon-man HWANG Young-kug 《Journal of Central South University》 SCIE EI CAS 2011年第1期153-158,共6页
Factors for determining the spindle size are the shaft diameter, positions of bearing and motor, and entire length of the spindle. Then, it is important to find the assembling of the optimal design variables, which sa... Factors for determining the spindle size are the shaft diameter, positions of bearing and motor, and entire length of the spindle. Then, it is important to find the assembling of the optimal design variables, which satisfy the stiffimss and rotational speed required to the spindle. A general full factorial design method was used to verify some factors that affect the natural frequency of a spindle. It is verified that the shorter shaft length and bearing span length represent the higher natural frequency, and there are some effects according to the change in the levels of factors. The detailed spindle dimension is determined by applying an EVD method, which can define the optimal bearing position through considering the limiting condition. Based on the estimated regression model, the optimal spindle size and bearing distance that can improve the primary natural frequency are obtained, and the influence of design factors on the natural frequency is also analyzed. 展开更多
关键词 high-speed spindle extreme vertices design natural frequency lightweight design full factorial design
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Thermal Influence of the Couette Flow in a Hydrostatic Spindle on the Machining Precision 被引量:5
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作者 CHEN Dongju FAN Jinwei +2 位作者 LI Haiyong WANG Xiaofeng ZHANG Feihu 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2013年第3期427-436,共10页
Hydrostatic spindles are increasingly used in precision machine tools. Thermal error is the key factor affecting the machining accuracy of the spindle, and research has focused on spindle thermal errors through examin... Hydrostatic spindles are increasingly used in precision machine tools. Thermal error is the key factor affecting the machining accuracy of the spindle, and research has focused on spindle thermal errors through examination of the influence of the temperature distribution, thermal deformation and spindle mode. However, seldom has any research investigated the thermal effects of the associated Couette flow. To study the heat transfer mechanism in spindle systems, the criterion of the heat transfer direction according to the temperature distribution of the Couette flow at different temperatures is deduced. The method is able to deal accurately with the significant phenomena occurring at every place where thermal energy flowed in such a spindle system. The variation of the motion error induced by thermal effects on a machine work-table during machining is predicated by establishing the thermo-mechanical error model of the hydrostatic spindle for a high precision machine tool. The flow state and thermal behavior of a hydrostatic spindle is analyzed with the evaluated heat power and the coefficients of the convective heat transfer over outer surface of the spindle are calculated, and the thermal influence on the oil film stiffness is evaluated. Thermal drift of the spindle nose is measured with an inductance micrometer, the thermal deformation data 1.35 μm after running for 4 h is consistent with the value predicted by the finite element analysis’s simulated result 1.28 μm, and this demonstrates that the simulation method is feasible. The thermal effects on the processing accuracy from the flow characteristics of the fluid inside the spindle are analyzed for the first time. 展开更多
关键词 hydrostatic spindle Couette flow finite element simulation convective heat transfer thermal deformation
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Torsional vibration analysis of lathe spindle system with unbalanced workpiece 被引量:5
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作者 郭瑞 JANG Sung-Hyun CHOI Young-Hyu 《Journal of Central South University》 SCIE EI CAS 2011年第1期171-176,共6页
For the purpose of analyzing the torsional vibration caused by the gravitational unbalance torque arisen in a spindle system when it is machining heavy work piece,a 10-DOF lumped parameter model was made for the machi... For the purpose of analyzing the torsional vibration caused by the gravitational unbalance torque arisen in a spindle system when it is machining heavy work piece,a 10-DOF lumped parameter model was made for the machine tool spindle system with geared transmission.By using the elementary method and Runge-Kutta method in Matlab,the eigenvalue problem was solved and the pure torsional vibration responses were obtained and examined.The results show that the spindle system cannot operate in the desired constant rotating speed as far as the gravitational unbalance torque is engaged,so it may cause bad effect on machining accuracy.And the torsional vibration increases infinitely near the resonant frequencies,so the spindle system cannot operate normally during these spindle speed ranges. 展开更多
关键词 unbalanced work piece gravitational unbalance torque torsional vibration spindle system geared transmission
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