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
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
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
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
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
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
Through analyzing the principle of spindle drive of winding mechanism for high speed spinning machine,the article not only describes a kind of mode of spindle drive for take-up motion on the basis of control method of...Through analyzing the principle of spindle drive of winding mechanism for high speed spinning machine,the article not only describes a kind of mode of spindle drive for take-up motion on the basis of control method of constant velocity winding, but also introduces the design technique of software and hardware for the control system of mechatronics of spindle drive mode for take- up motion on the basis of constant velocity winding for high speed spinning machine with single-chip microcomputer. The mathematical model to describe the spindle rotating speed is established. It is an important technology for high speed spinning machine and provides a feasible application way.展开更多
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
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
In this paper, an analytical scientific approach is presented for the design and analysis of an air-turbine-driven paint spray spindle, and it is used to improve further the design concept of the existing spindle appl...In this paper, an analytical scientific approach is presented for the design and analysis of an air-turbine-driven paint spray spindle, and it is used to improve further the design concept of the existing spindle applied in automotive coating and paint spraying applications. The current spindle on the market can operate at a maximum speed of 100,000 rpm and features a maximum bell size of 70 mm diameter. Given the increasing demands for high automotive coating/painting quality and productivity in assembly, the design and development of a paint spray spindle with a speed of 145,000 rpm or higher is needed. Computational fluid dynamics(CFD)-based simulation is applied in the approach. Accordingly, CFD simulation-based design and analysis are undertaken, covering the characteristic factors of velocity, pressure of the air supply, rotational speed of the air-turbine, and torque and force reaction on the turbine blades. Furthermore, the turbine blade geometric shape is investigated through the simulations. Three geometrical concepts have been investigated against the original model. The results on Concept_03 verified the higher angular velocity speeds against the theoretical model. The pressure and velocity effects in the blades have been investigated. The results show that the pressure and velocity of the air supply driving the turbine are critical factors influencing the stability of turbine spinning. The results also demonstrate that the force acting on the blades is at the highest level when the adjacent face changes from a straight surface into a curve. Finally, changing the geometrical shape in the turbine likely increases the tangential air pressure at the blades surface and relatively increases the magnitude of the lateral torque and force in the spindle. Notwithstanding this condition, the analytical values surpass the theoretical target values.展开更多
Objective In drugs for i nvigorating blood circulation, to find a herb that can stimulate afferent discha rge of muscle spindle. Methods A single muscle spindle was isolated from sartorial mus cle of toad. Using air-g...Objective In drugs for i nvigorating blood circulation, to find a herb that can stimulate afferent discha rge of muscle spindle. Methods A single muscle spindle was isolated from sartorial mus cle of toad. Using air-gap technique, afferent discharge of the muscle spindle was recorded. Effects of Angelica Sinensis, Salvia Miltiorrhiza, and Safflower o n afferent discharge of the muscle spindle were observed. Results Angelica Sinensis could distinctly increase afferent di scharge frequency of the muscle spindle, and this increase was dose-dependent. But Salvia Miltiorrhiza and Safflower had no this excitatory effect. Conclusion It is known that Angelica Sinensis can invigorate bl ood circulation, and we have found its excitatory effect on muscle spindle which makes it possible to serve people with muscle atrophy if more evidences from cl inical experiments are available.展开更多
Objective To analyse the antinociceptive effect of red nucleus (RN) and its role in the antinociceptive effect of muscle spindle afferents. Methods The single units of RN or wide dynamic range (WDR) neuron in the spin...Objective To analyse the antinociceptive effect of red nucleus (RN) and its role in the antinociceptive effect of muscle spindle afferents. Methods The single units of RN or wide dynamic range (WDR) neuron in the spinal cord dorsal horn were extracelluarly recorded. The effects of RN stimulation on nociceptive responses (C fibers evoked responses, C responses) of WDR neurons were observed. The influence of muscle spindle afferents elicited by intravenous administration of succinylcholine (Sch) on the spontaneous discharge of RN neurons and on C responses of WDR neurons were observed. The effect of muscle spindle afferents on C responses of WDR neurons after unilateral lesions of RN was also observed. Results Electrical stimulation of the RN produced a significantly inhibitory effect on the nociceptive responses of WDR neurons. RN neurons were excited by muscle spindle afferents. Muscle spindle afferents significantly inhibited C response of WDR neurons and this inhibitory effect was reduced by lesions of RN. Conclusion RN neurons have a significant antinociceptive effect and might be involved in the antinociceptive effects elicited by muscle spindle afferents.展开更多
Aero-engine spindle ball bearings work in harsh conditions which are affected by relatively complex stresses. One of the key factors which affects bearing performance is its structure. In this paper,we used reliabilit...Aero-engine spindle ball bearings work in harsh conditions which are affected by relatively complex stresses. One of the key factors which affects bearing performance is its structure. In this paper,we used reliability based design optimization method to solve the structure design problem of aero-engine spindle ball bearings.Compared with the optimization design method, the value of equivalent dynamic load using reliability optimization design method was the least by MATLAB simulation. Also the design solutions show that the optimized structure possesses higher reliability than the original solution.展开更多
This paper introduces a system of computer aided assembly process planning for spindle box of NC lathe. The method of describing assembly information and generating assembly process drawing is presented. The principle...This paper introduces a system of computer aided assembly process planning for spindle box of NC lathe. The method of describing assembly information and generating assembly process drawing is presented. The principles of decision for assembly sequence ar展开更多
This paper focuses on model development for computer analysis of the thermal behavior of an externally driven spindle. The aim of the developed model is to enable efficient quantitative estimation of the thermal chara...This paper focuses on model development for computer analysis of the thermal behavior of an externally driven spindle. The aim of the developed model is to enable efficient quantitative estimation of the thermal characteristics of the main spindle unit in an early stage of the development process. The presented work includes an experimental validation of the simulation model using a custom-built test rig. Specifically, the effects of the heat generated in the bearings and the heat flux from the bearing to the adjacent spindle system elements are investigated. Simulation and experimental results are compared and demonstrate good accordance. The proposed model is a useful, efficient and validated tool for quantitative simulation of thermal behavior of a main spindle system.展开更多
The spindle barrel finishing is commonly used to improve the surface integrity of the important parts of the high-end equipment while it is difficult to provide enough test artifacts for the traditional trial and erro...The spindle barrel finishing is commonly used to improve the surface integrity of the important parts of the high-end equipment while it is difficult to provide enough test artifacts for the traditional trial and error experiment to obtain the desirable processing technology.The EDEM simulation of the spindle barrel finishing can provide effective help for the process design,however,the difference between the simulation and experiment is closely related to the selection of the contact model during simulation.In this paper,simulations and experiments are conducted based on the identical apparatus and conditions to facilitate the comparison and validation between each other.Based on the Hertz contact theory,the effect of the material properties of contact objects and the relative position of the workpiece on the contact force is qualified.The expression of the correlation coefficient of the contact model is deduced.Then the formula for calculating the contact force between the barrel finishing abrasive and the workpiece that includes influence coefficient of the material properties and the relative positions is established.Finally,the contact force calculation formula is verified by changing the rotating speed.The result shows that the material correction coefficient ranges from 1.41 to 2.38,which is inversely related to the equivalent modulus E.The position correction coefficient ranges from 2.0 to 2.3.The relative error value between the calculation result and the experimental test result is from 0.58%to 14.07%.This research lay a theoretical foundation for the correction theory of the core elements of the spindle barrel finishing process.展开更多
Based on the mechanical system of free-end fibers and the analysis of pulling free-end fibers out of the spun yarn during spinning,a low-fiber hollow spindle is designed and the air distribution of fluent field is sim...Based on the mechanical system of free-end fibers and the analysis of pulling free-end fibers out of the spun yarn during spinning,a low-fiber hollow spindle is designed and the air distribution of fluent field is simulated numerically. The negative pressure effect is much bigger at the top of low-fiber hollow spindle than that in Murata No.861,which is more conducive for single fiber to get into the channel of hollow spindle. The tangential velocity in 0-3 mm at the top of hollow spindle increases and the fluctuation of radial velocity is much stronger,which enhance the wrapping effect. In the addition,the distribution of axial velocity remains the same.展开更多
The axial magnetic force, induced by the complicated flux linkage distribution from rotor magnet and stator slotted, is constructed by different relative heights and calculated by 3D finite element method (FEM) to ana...The axial magnetic force, induced by the complicated flux linkage distribution from rotor magnet and stator slotted, is constructed by different relative heights and calculated by 3D finite element method (FEM) to analyze the dynamic characteristics for a DVD spindle motor. The axial magnetic force is designed to provide an axial stiffness and govern the natural frequency of the dynamic performance. According to the simulation results and experimental measurements, the dynamic behaviors are significantly improved with a variation of relative height of rotor magnet and stator slotted on a DVD spindle motor.展开更多
Spindle cell carcinoma of head and neck, a subtype of squamous cell carcinoma is a unique and rare neoplasm. It has a more aggressive behavior as compared to classical squomous cell carcinoma warranting surgical inter...Spindle cell carcinoma of head and neck, a subtype of squamous cell carcinoma is a unique and rare neoplasm. It has a more aggressive behavior as compared to classical squomous cell carcinoma warranting surgical interventions with wider surgical margins. Immunohistochemistry along with routine histopathology is essential in establishing the diagnosis of spindle cell carcinoma. We at Dr. B. Borooah Cancer Institute, Guwahati, a regional institute for treatment and research, hereby report 40 cases of such lesion with clinicopathological and immunohistochemical study. Out of total 40 cases included in the study group most of the cases were in the age group of 40 to 60 years. Commonest site of presentation was nasopharynx and buccal mucosa. 14 cases of the oral cavity (buccal mucosa, alveolus, oral tongue and hard palate) were treated with surgery. All the cases with disease of the larynx and hypopharynx were treated with radiotherapy and cases involving the nasopharynx received radiotherapy and chemotherapy. In the surgery group recurrence rate was found to be 71.4% and metastasis rate was 21.4%. Biopsy specimens were subjected to histopathological examination followed by immunohistochemistry. Immunohistochemical analysis show concurrent presence of malignant epithelial and sarcomatoid spindle cell components by co-expression of cytokeratin (CK) and vimentin to various degrees.展开更多
基金supported by the Ministry of Science and Technology,Taiwan,under Grant MOST 110-2218-E-194-010。
文摘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.
基金funded by the Guangdong Basic and Applied Basic Research Foundation(Grant Nos.2021A1515011853 and 2020A1515110294)the National Natural Science Foundation of China(Grant Nos.61906019 and 62076103)+2 种基金STI 2030-Major Projects 2022ZD0208900Guangzhou Science and Technology Plan Project(Grant No.202102020877)the Guangzhou Science and Technology Plan Project Key Field R&D Project(202007030005).
文摘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.
文摘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.
基金Beijing Hope Run Special Fund of Cancer Foundation of China,No.LC2020L05.
文摘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.
基金supported by National Natural Science Foundation of China (Grant Nos. 51105005, 51275014)Ministry of Education of China (Grant No. 20111103120002)
文摘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.
文摘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.
文摘Through analyzing the principle of spindle drive of winding mechanism for high speed spinning machine,the article not only describes a kind of mode of spindle drive for take-up motion on the basis of control method of constant velocity winding, but also introduces the design technique of software and hardware for the control system of mechatronics of spindle drive mode for take- up motion on the basis of constant velocity winding for high speed spinning machine with single-chip microcomputer. The mathematical model to describe the spindle rotating speed is established. It is an important technology for high speed spinning machine and provides a feasible application way.
文摘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.
文摘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.
基金the PhD Scholarship Support at Brunel University London
文摘In this paper, an analytical scientific approach is presented for the design and analysis of an air-turbine-driven paint spray spindle, and it is used to improve further the design concept of the existing spindle applied in automotive coating and paint spraying applications. The current spindle on the market can operate at a maximum speed of 100,000 rpm and features a maximum bell size of 70 mm diameter. Given the increasing demands for high automotive coating/painting quality and productivity in assembly, the design and development of a paint spray spindle with a speed of 145,000 rpm or higher is needed. Computational fluid dynamics(CFD)-based simulation is applied in the approach. Accordingly, CFD simulation-based design and analysis are undertaken, covering the characteristic factors of velocity, pressure of the air supply, rotational speed of the air-turbine, and torque and force reaction on the turbine blades. Furthermore, the turbine blade geometric shape is investigated through the simulations. Three geometrical concepts have been investigated against the original model. The results on Concept_03 verified the higher angular velocity speeds against the theoretical model. The pressure and velocity effects in the blades have been investigated. The results show that the pressure and velocity of the air supply driving the turbine are critical factors influencing the stability of turbine spinning. The results also demonstrate that the force acting on the blades is at the highest level when the adjacent face changes from a straight surface into a curve. Finally, changing the geometrical shape in the turbine likely increases the tangential air pressure at the blades surface and relatively increases the magnitude of the lateral torque and force in the spindle. Notwithstanding this condition, the analytical values surpass the theoretical target values.
文摘Objective In drugs for i nvigorating blood circulation, to find a herb that can stimulate afferent discha rge of muscle spindle. Methods A single muscle spindle was isolated from sartorial mus cle of toad. Using air-gap technique, afferent discharge of the muscle spindle was recorded. Effects of Angelica Sinensis, Salvia Miltiorrhiza, and Safflower o n afferent discharge of the muscle spindle were observed. Results Angelica Sinensis could distinctly increase afferent di scharge frequency of the muscle spindle, and this increase was dose-dependent. But Salvia Miltiorrhiza and Safflower had no this excitatory effect. Conclusion It is known that Angelica Sinensis can invigorate bl ood circulation, and we have found its excitatory effect on muscle spindle which makes it possible to serve people with muscle atrophy if more evidences from cl inical experiments are available.
基金ThisresearchwassupportedbytheNationalNaturalScienceFoundationofChina (No .3 90 70 3 3 4)
文摘Objective To analyse the antinociceptive effect of red nucleus (RN) and its role in the antinociceptive effect of muscle spindle afferents. Methods The single units of RN or wide dynamic range (WDR) neuron in the spinal cord dorsal horn were extracelluarly recorded. The effects of RN stimulation on nociceptive responses (C fibers evoked responses, C responses) of WDR neurons were observed. The influence of muscle spindle afferents elicited by intravenous administration of succinylcholine (Sch) on the spontaneous discharge of RN neurons and on C responses of WDR neurons were observed. The effect of muscle spindle afferents on C responses of WDR neurons after unilateral lesions of RN was also observed. Results Electrical stimulation of the RN produced a significantly inhibitory effect on the nociceptive responses of WDR neurons. RN neurons were excited by muscle spindle afferents. Muscle spindle afferents significantly inhibited C response of WDR neurons and this inhibitory effect was reduced by lesions of RN. Conclusion RN neurons have a significant antinociceptive effect and might be involved in the antinociceptive effects elicited by muscle spindle afferents.
文摘Aero-engine spindle ball bearings work in harsh conditions which are affected by relatively complex stresses. One of the key factors which affects bearing performance is its structure. In this paper,we used reliability based design optimization method to solve the structure design problem of aero-engine spindle ball bearings.Compared with the optimization design method, the value of equivalent dynamic load using reliability optimization design method was the least by MATLAB simulation. Also the design solutions show that the optimized structure possesses higher reliability than the original solution.
文摘This paper introduces a system of computer aided assembly process planning for spindle box of NC lathe. The method of describing assembly information and generating assembly process drawing is presented. The principles of decision for assembly sequence ar
文摘This paper focuses on model development for computer analysis of the thermal behavior of an externally driven spindle. The aim of the developed model is to enable efficient quantitative estimation of the thermal characteristics of the main spindle unit in an early stage of the development process. The presented work includes an experimental validation of the simulation model using a custom-built test rig. Specifically, the effects of the heat generated in the bearings and the heat flux from the bearing to the adjacent spindle system elements are investigated. Simulation and experimental results are compared and demonstrate good accordance. The proposed model is a useful, efficient and validated tool for quantitative simulation of thermal behavior of a main spindle system.
基金Supported by Program National Natural Science Foundation of China(Grant Nos.51875389,51975399,52075362)Key Program of Natural Science Foundation of Shanxi Province of China(Grant No.201801D111002)Scientific and Technological Innovation Project for Excellent Talents in Shanxi Province of China(Grant No.201805D211031).
文摘The spindle barrel finishing is commonly used to improve the surface integrity of the important parts of the high-end equipment while it is difficult to provide enough test artifacts for the traditional trial and error experiment to obtain the desirable processing technology.The EDEM simulation of the spindle barrel finishing can provide effective help for the process design,however,the difference between the simulation and experiment is closely related to the selection of the contact model during simulation.In this paper,simulations and experiments are conducted based on the identical apparatus and conditions to facilitate the comparison and validation between each other.Based on the Hertz contact theory,the effect of the material properties of contact objects and the relative position of the workpiece on the contact force is qualified.The expression of the correlation coefficient of the contact model is deduced.Then the formula for calculating the contact force between the barrel finishing abrasive and the workpiece that includes influence coefficient of the material properties and the relative positions is established.Finally,the contact force calculation formula is verified by changing the rotating speed.The result shows that the material correction coefficient ranges from 1.41 to 2.38,which is inversely related to the equivalent modulus E.The position correction coefficient ranges from 2.0 to 2.3.The relative error value between the calculation result and the experimental test result is from 0.58%to 14.07%.This research lay a theoretical foundation for the correction theory of the core elements of the spindle barrel finishing process.
基金Program for Changjiang Scholars and Innovative Research Team in University,China(No.IRT1220)Shanghai Natural Science Foundation,China(No.13ZR1400900)Keygrant Project of Chinese Ministry of Education(No.113027A)
文摘Based on the mechanical system of free-end fibers and the analysis of pulling free-end fibers out of the spun yarn during spinning,a low-fiber hollow spindle is designed and the air distribution of fluent field is simulated numerically. The negative pressure effect is much bigger at the top of low-fiber hollow spindle than that in Murata No.861,which is more conducive for single fiber to get into the channel of hollow spindle. The tangential velocity in 0-3 mm at the top of hollow spindle increases and the fluctuation of radial velocity is much stronger,which enhance the wrapping effect. In the addition,the distribution of axial velocity remains the same.
文摘The axial magnetic force, induced by the complicated flux linkage distribution from rotor magnet and stator slotted, is constructed by different relative heights and calculated by 3D finite element method (FEM) to analyze the dynamic characteristics for a DVD spindle motor. The axial magnetic force is designed to provide an axial stiffness and govern the natural frequency of the dynamic performance. According to the simulation results and experimental measurements, the dynamic behaviors are significantly improved with a variation of relative height of rotor magnet and stator slotted on a DVD spindle motor.
文摘Spindle cell carcinoma of head and neck, a subtype of squamous cell carcinoma is a unique and rare neoplasm. It has a more aggressive behavior as compared to classical squomous cell carcinoma warranting surgical interventions with wider surgical margins. Immunohistochemistry along with routine histopathology is essential in establishing the diagnosis of spindle cell carcinoma. We at Dr. B. Borooah Cancer Institute, Guwahati, a regional institute for treatment and research, hereby report 40 cases of such lesion with clinicopathological and immunohistochemical study. Out of total 40 cases included in the study group most of the cases were in the age group of 40 to 60 years. Commonest site of presentation was nasopharynx and buccal mucosa. 14 cases of the oral cavity (buccal mucosa, alveolus, oral tongue and hard palate) were treated with surgery. All the cases with disease of the larynx and hypopharynx were treated with radiotherapy and cases involving the nasopharynx received radiotherapy and chemotherapy. In the surgery group recurrence rate was found to be 71.4% and metastasis rate was 21.4%. Biopsy specimens were subjected to histopathological examination followed by immunohistochemistry. Immunohistochemical analysis show concurrent presence of malignant epithelial and sarcomatoid spindle cell components by co-expression of cytokeratin (CK) and vimentin to various degrees.
