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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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Functions of spindle check-point and its relationship to chromosome instability 被引量:2
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作者 Jianhui Yao Yupeng Zheng Xuebiao Yao 《Chinese Science Bulletin》 SCIE EI CAS 2002年第8期617-623,共7页
It is generally believed that the equal distribution of genetic materials to two daughter cells during mitosis is the key to cell health and development. During the dynamic process, spindle checkpoint plays a very imp... It is generally believed that the equal distribution of genetic materials to two daughter cells during mitosis is the key to cell health and development. During the dynamic process, spindle checkpoint plays a very important role in chromosome movements and final sister chromatid separation. The equal and precise segregation of chromosomes contributes to the genomic stability while aberrant separations result in chromosome instability that causes pathogenesis of certain diseases such as Down’s syndrome and cancers. Kinetochore and its regulatory proteins consist of the spindle checkpoint and determine the spatial and temporal orders of chromosome segregation. 展开更多
关键词 spindle CHECKPOINT KINETOCHORE CHROMOSOME INSTABILITY cancer.
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An Efficient Sleep Spindle Detection Algorithm Based on MP and LSBoost
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作者 Fei Wang Li Li +6 位作者 Yinxing Wan Zhuorong Li Lixian Luo Bangshun Hu Jiahui Pan Zhenfu Wen Haiyun Huang 《Computers, Materials & Continua》 SCIE EI 2023年第8期2301-2316,共16页
Sleep spindles are an electroencephalogram(EEG)biomarker of non-rapid eye movement(NREM)sleep and have important implications for clinical diagnosis and prognosis.However,it is challenging to accurately detect sleep s... Sleep spindles are an electroencephalogram(EEG)biomarker of non-rapid eye movement(NREM)sleep and have important implications for clinical diagnosis and prognosis.However,it is challenging to accurately detect sleep spindles due to the complexity of the human brain and the uncertainty of neural mechanisms.To improve the reliability and objectivity of sleep spindle detection and to compensate for the limitations of manual annotation,this study proposes a new automatic detection algorithm based on Matching Pursuit(MP)and Least Squares Boosting(LSBoost),where the automatic sleep spindle detection algorithm can help reduce the visual annotation workload of sleep clinicians.Specifically,MP is a time-frequency analysis method suitable for extracting spindle wave characteristics,which can accurately locate spindle waves on a time-frequency plane.LSBoost is an ensemble learning classification method to deal with unbalanced data.Initially,theMP method is used to search for EEG segments that are possible spindle waves from the filtered raw EEG data.Then,the designed feature segments are thrown into the LSBoost classifier to further identify the real spindles from all candidates and output the final results.The proposed method is verified on the common public dataset DREAMS.The experiment results showthat the sensitivity and F1-scores based on the sample-based assessments achieve 68.2% and 55.4%,respectively.Furthermore,the Recall and F1-score based on the event assessments are 83.8% and 70.8%,respectively.These results show that the proposed algorithm is robust to the subject changes in the DREAMS dataset.In addition,it improves the quality of sleep spindle detection,which is expected to assist the manual marking of experts. 展开更多
关键词 Sleep spindles detection EEG SLEEP
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Ensemble Model for Spindle Thermal Displacement Prediction of Machine Tools
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作者 Ping-Huan Kuo Ssu-Chi Chen +2 位作者 Chia-Ho Lee Po-Chien Luan Her-Terng Yau 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第10期319-343,共25页
Numerous factors affect the increased temperature of a machine tool, including prolonged and high-intensity usage,tool-workpiece interaction, mechanical friction, and elevated ambient temperatures, among others. Conse... Numerous factors affect the increased temperature of a machine tool, including prolonged and high-intensity usage,tool-workpiece interaction, mechanical friction, and elevated ambient temperatures, among others. Consequently,spindle thermal displacement occurs, and machining precision suffers. To prevent the errors caused by thetemperature rise of the Spindle fromaffecting the accuracy during themachining process, typically, the factory willwarm up themachine before themanufacturing process.However, if there is noway to understand the tool spindle’sthermal deformation, the machining quality will be greatly affected. In order to solve the above problem, thisstudy aims to predict the thermal displacement of the machine tool by using intelligent algorithms. In the practicalapplication, only a few temperature sensors are used to input the information into the prediction model for realtimethermal displacement prediction. This approach has greatly improved the quality of tool processing.However,each algorithm has different performances in different environments. In this study, an ensemble model is used tointegrate Long Short-TermMemory (LSTM) with Support VectorMachine (SVM). The experimental results showthat the prediction performance of LSTM-SVM is higher than that of other machine learning algorithms. 展开更多
关键词 Thermal displacement ensemble model LSTM milling machine spindle
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High spindle and kinetochore-associated complex subunit-3 expression predicts poor prognosis and correlates with adverse immune infiltration in hepatocellular carcinoma
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作者 Lin-Lin Zheng Ya-Ru Wang +9 位作者 Zhen-Rong Liu Zhi-Hao Wang Chang-Cheng Tao Yong-Gang Xiao Kai Zhang An-Ke Wu Hai-Yang Li Jian-Xiong Wu Ting Xiao Wei-Qi Rong 《World Journal of Gastrointestinal Surgery》 SCIE 2023年第8期1600-1614,共15页
BACKGROUND Spindle and kinetochore-associated complex subunit 3(SKA3)is a malignancyassociated gene that plays a critical role in the regulation of chromosome separation and cell division.However,the molecular mechani... BACKGROUND Spindle and kinetochore-associated complex subunit 3(SKA3)is a malignancyassociated gene that plays a critical role in the regulation of chromosome separation and cell division.However,the molecular mechanism through which SKA3 regulates tumor cell proliferation in hepatocellular carcinoma(HCC)has not been fully elucidated.AIM To investigate the molecular mechanisms underlying the role of SKA3 in HCC.METHODS SKA3 expression,clinicopathological,and survival analyses were performed using multiple public database platforms,and the results were verified by Western blot and immunohistochemistry staining using collected clinical samples.Functional enrichment analyses were performed to evaluate the biological functions and molecular mechanisms of SKA3 in HCC.Furthermore,the Tumor Immune Estimation Resource and single-sample Gene Set Enrichment Analysis(ssGSEA)algorithms were utilized to investigate the abundance of tumor-infiltrating immune cells in HCC.The response to chemotherapeutic drugs was evaluated by the R package“pRRophetic”.RESULTS We found that upregulated SKA3 expression was significantly correlated with poor prognosis in patients with HCC.Multivariable Cox regression analysis indicated that SKA3 was an independent risk factor for survival.GSEA revealed that SKA3 expression may facilitate proliferation and migratory processes by regulating the cell cycle and DNA repair.Moreover,patients with high SKA3 expression had significantly decreased ratios of CD8+T cells,natural killer cells,and dendritic cells.Drug sensitivity analysis showed that the high SKA3 group was more sensitive to sorafenib,sunitinib,paclitaxel,doxorubicin,gemcitabine,and vx-680.CONCLUSION High SKA3 expression led to poor prognosis in patients with HCC by enhancing HCC proliferation and repressing immune cell infiltration surrounding HCC.SKA3 may be used as a biomarker for poor prognosis and as a therapeutic target in HCC. 展开更多
关键词 spindle and kinetochore-associated protein 3 Hepatocellular carcinoma Prognosis Immune infiltration cells
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Managing spindle cell sarcoma with surgery and high-intensity focused ultrasound:A case report
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作者 Ying-Qiong Zhu Gan-Chao Zhao +2 位作者 Chen-Xi Zheng Lei Yuan Geng-Biao Yuan 《World Journal of Clinical Cases》 SCIE 2023年第27期6551-6557,共7页
BACKGROUND Undifferentiated pleomorphic sarcomas,also known as spindle cell sarcomas,are a relatively uncommon subtype of soft tissue sarcomas in clinical practice.CASE SUMMARY We present a case report of a 69-year-ol... BACKGROUND Undifferentiated pleomorphic sarcomas,also known as spindle cell sarcomas,are a relatively uncommon subtype of soft tissue sarcomas in clinical practice.CASE SUMMARY We present a case report of a 69-year-old female patient who was diagnosed with undifferentiated spindle cell soft tissue sarcoma on her left thigh.Surgical excision was initially performed,but the patient experienced a local recurrence following multiple surgeries and radioactive particle implantations.High-intensity focused ultrasound(HIFU)was subsequently administered,resulting in complete ablation of the sarcoma without any significant complications other than bone damage at the treated site.However,approximately four months later,the patient experienced a broken lesion at the original location.After further diagnostic workup,the patient underwent additional surgery and is currently stable with a good quality of life.CONCLUSION HIFU has shown positive outcomes in achieving local control of limb spindle cell sarcoma,making it an effective non-invasive treatment option. 展开更多
关键词 spindle cell sarcoma High-intensity focused ultrasound Cancer therapy 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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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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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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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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Deficit of mitochondria-derived ATP during oxidative stress impairs mouse MII oocyte spindles 被引量:24
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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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Hydrothermal synthesis of spindle-like Li_2FeSiO_4-C composite as cathode materials for lithium-ion batteries 被引量:4
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作者 Haiyan Gao Zhe Hu +3 位作者 Kai Zhang Fangyi Cheng Zhanliang Tao Jun Chen 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2014年第3期274-281,共8页
In this paper,we report on the preparation of Li2FeSiO4,sintered Li2FeSiO4,and Li2FeSiO4-C composite with spindle-like morphologies and their application as cathode materials of lithium-ion batteries.Spindle-like Li2F... In this paper,we report on the preparation of Li2FeSiO4,sintered Li2FeSiO4,and Li2FeSiO4-C composite with spindle-like morphologies and their application as cathode materials of lithium-ion batteries.Spindle-like Li2FeSi04 was synthesized by a facile hydrothermal method with(NH4)2Fe(SO4)2 as the iron source.The spindle-like Li2FeSiO4 was sintered at 600 ℃ for 6 h in Ar atmosphere.Li2FeSiO4-C composite was obtained by the hydrothermal treatment of spindle-like Li2FeSiO4 in glucose solution at 190 ℃ for 3 h.Electrochemical measurements show that after carbon coating,the electrode performances such as discharge capacity and high-rate capability are greatly enhanced.In particular.Li2FeSiO4-C with carbon content of 7.21 wt%delivers the discharge capacities of 160.9 mAh·g-1 at room temperature and 213 mAh·g-1 at45℃(0.1 C),revealing the potential application in lithium-ion batteries. 展开更多
关键词 Li2FeSiO4-C composite spindle like hydrothermal synthesis cathode material lithium-ion battery
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MECHANICAL-ELECTRIC COUPLING DYNAMICAL CHARACTERISTICS OF AN ULTRA-HIGH SPEED GRINDING MOTORIZED SPINDLE SYSTEM 被引量:23
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作者 LUE Lang XIONG Wanli GAO Hang 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2008年第5期34-40,共7页
On the basis of the traditional mechanical model of a grinding wheel rotor and the mechanical-electric coupling model with ideal sinusoidal supply, taking high-frequency converting current of inverter power switches i... On the basis of the traditional mechanical model of a grinding wheel rotor and the mechanical-electric coupling model with ideal sinusoidal supply, taking high-frequency converting current of inverter power switches into further consideration, a modified mechanical-electric coupling model is created. The created model consists of an inverter, a motorized spindle, a grinding wheel and grinding loads. Some typical non-stationary processes of the grinding system with two different supplies, including the starting, the speed rising and the break in grinding loads, are compared by making use of the created model. One supply is an ideal sinusoidal voltage source, the other is an inverter. The theoretical analysis of the high-order harmonic is also compared with the experimental result. The material strategy of suppressing high-order harmonic mechanical-electric coupling vibration by optimizing inverter operating parameters is proposed. 展开更多
关键词 Ultra-high speed grinding Motorized spindle Mechanical-electric coupling Vibration Suppression
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Experimental Study on Meiotic Spindles and Chromosomes of Mouse Mature (MⅡ) Stage Oocytes under Laser Scanning Confocal Microscopy 被引量:2
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作者 王雁林 朱桂金 +1 位作者 李霞 李小兰 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2006年第3期353-355,共3页
Taking the mouse as a model, the experimental method of observing the morphology of meiotic spindles and chromosomes in mature oocytes were investigated in order to evaluate the effects of various interventions on the... Taking the mouse as a model, the experimental method of observing the morphology of meiotic spindles and chromosomes in mature oocytes were investigated in order to evaluate the effects of various interventions on the quality of oocytes accurately and rapidly. Laser scanning confocal microscope (LSCM) was used to examine the meiotic spindles and chromosomes by the technologies of optical section and three-dimensional (3D) image reconstruction. The results showed that the configurations of meiotic spindles and chromosomes could be observed clearly by LSCM. The normal rate of meiotic spindles and chromosomes was 82% and 86% respectively. It was concluded that the LSCM was a valid instrument to observe the meiotic spindles and chromosomes of mature oocytes and could be used as a valid method to evaluate the quality of MⅡocytes. 展开更多
关键词 laser scanning fonfocal microscope OOCYTES spindle CHROMOSOME
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Optimization of Bearing Locations for Maximizing First Mode Natural Frequency of Motorized Spindle-Bearing Systems Using a Genetic Algorithm 被引量:4
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作者 Chi-Wei Lin 《Applied Mathematics》 2014年第14期2137-2152,共16页
This paper has developed a genetic algorithm (GA) optimization approach to search for the optimal locations to install bearings on the motorized spindle shaft to maximize its first-mode natural frequency (FMNF). First... This paper has developed a genetic algorithm (GA) optimization approach to search for the optimal locations to install bearings on the motorized spindle shaft to maximize its first-mode natural frequency (FMNF). First, a finite element method (FEM) dynamic model of the spindle-bearing system is formulated, and by solving the eigenvalue problem derived from the equations of motion, the natural frequencies of the spindle system can be acquired. Next, the mathematical model is built, which includes the objective function to maximize FMNF and the constraints to limit the locations of the bearings with respect to the geometrical boundaries of the segments they located and the spacings between adjacent bearings. Then, the Sequential Decoding Process (SDP) GA is designed to accommodate the dependent characteristics of the constraints in the mathematical model. To verify the proposed SDP-GA optimization approach, a four-bearing installation optimazation problem of an illustrative spindle system is investigated. The results show that the SDP-GA provides well convergence for the optimization searching process. By applying design of experiments and analysis of variance, the optimal values of GA parameters are determined under a certain number restriction in executing the eigenvalue calculation subroutine. A linear regression equation is derived also to estimate necessary calculation efforts with respect to the specific quality of the optimization solution. From the results of this illustrative example, we can conclude that the proposed SDP-GA optimization approach is effective and efficient. 展开更多
关键词 Optimal DESIGN Motorized spindle System DESIGN Finite Element Method Genetic Algorithm FIRST MODE Natural Frequency
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THE ROLE OF BRAIN-STEM DISCENDING INHIBITORY SYSTEM IN THE ANTINOCICEPTIVE EFFECT ELICITED BY MUSCLE SPINDLE AFFERENTS 被引量:3
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作者 吴苏娣 樊小力 +1 位作者 汪丛莹 唐斌 《Academic Journal of Xi'an Jiaotong University》 2001年第2期152-155,共4页
Objective To analyse the antinociceptive effect of muscle spindle afferents and the involved mechanism.Methods The single unit of wide dynamic range neurons in the spinal cord dorsal horn were recorded extracelluarly.... Objective To analyse the antinociceptive effect of muscle spindle afferents and the involved mechanism.Methods The single unit of wide dynamic range neurons in the spinal cord dorsal horn were recorded extracelluarly.The effects of muscle spindle afferents elicited by intravenous administration of succinylcholine on nociceptive responses (C fibres evoked responses,C responses) of WDR neurons were observed before and after bilateral lesions of ventrolateral periaqueduct gray .And the effects of muscle spindle afferents on the spontaneous discharge of the tail flick related cell in the rostral ventro medial medulla and on the spontaneous discharge of the PAG neurons were observed.Results The C responses of WDR neurons were significantly inhibited by muscle spindle afferents,and the inhibitory effects were reduced by bilateral lesions of ventrolateral PAG.The spontaneous discharge of the off cell in the RVM was excited while the on cell was inhibited by intravenous administration of Sch.The spontaneous discharge of the PAG neurons were excited by muscle spindle afferents.Conclusion Muscle spindle afferents show a distinct effect of antinociception.PAG RVM descending inhibitory system may play an important role in this nociceptive modulative mechanism. 展开更多
关键词 muscle spindle ANTINOCICEPTION WDR neurons SUCCINYLCHOLINE PAG RVM
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Thermal Model of High-Speed Spindle Units 被引量:3
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作者 Jeong-Du Kim Igor Zverv Keon-Beom Lee 《Intelligent Information Management》 2010年第5期306-315,共10页
For the purpose to facilitate development of high-speed Spindle Units (SUs) running on rolling bearings, we have developed a beam element model, algorithms, and software for computer analysis of thermal characteristic... For the purpose to facilitate development of high-speed Spindle Units (SUs) running on rolling bearings, we have developed a beam element model, algorithms, and software for computer analysis of thermal characteristics of SUs. The thermal model incorporates a model of heat generation in rolling bearings, a model of heat transfer from bearings, and models for estimation of temperature and temperature deformations of SU elements. We have carried out experimental test and made quantitative evaluation of the effect of operation conditions on friction and thermal characteristics of the SUs of grinding and turning machines of typical structures. It is found that the operation conditions make stronger effect on SU temperatures when rpm increases. A comparison between the results of analysis and experiment proves their good mutual correspondence and allows us to recommend application of the models and software developed for design and research of high-speed SUs running on rolling bearings. 展开更多
关键词 THERMAL Model HIGH-SPEED spindle UNIT ROLLING BEARING
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