Sensory reinnervation of muscle spindles after repair of tibial nerve defects using autogenous vein grafts

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.

Deficit of mitochondria-derived ATP during oxidative stress impairs mouse MII oocyte spindles

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.

Experimental Study on Meiotic Spindles and Chromosomes of Mouse Mature (MⅡ) Stage Oocytes under Laser Scanning Confocal Microscopy

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.

Phosphorylated vasodilator-stimulated phosphoprotein is localized on mitotic spindles of the gastric cancer cell line SGC-7901

AIM： To elucidate the localization of vasodilator stimulated phosphoprotein （VASP）, a cytoskeletal organizing protein and a substrate of protein kinases A and G in mitotic gastric cancer cells. METHODS： Immunofluorescence microscopy was used to observe the localization of α-tubulin, VASP and Ser157 phosphorylated VASP （p-VASP） in interphase of mitotic gastric cancer of the cell line SGC-7901. RESULTS： Immunofluorescence staining showed that p-VASP but not VASP was co-localized with α-tubulin on spindle poles and fibers in prophase, metaphase and anaphase of the mitotic process of the gastric cancer cell line SGC-7901. H89, an inhibitor of protein kinases A and G, had no effect on the localization of p-VASP on the spindles. CONCLUSION： VASP may play a role in assembling and stabilizing the mitotic spindle of cells, and phosphorylation of the protein is the precondition for it to exert this function.

Model of Rotation Accuracy of High-Speed Spindles on Ball Bearings

For the purpose to improve a design quality of high-speed spindle units, we have developed mathematical models and software to simulate a rotation accuracy of spindles running on ball bearings. In order to better understand the mechanics of ball bearings, the dynamic interaction of ball bearings and spindle unit, and the influence of the bearing imperfections on the spindle rotation accuracy, we have carried out computer aided analysis and experimental studies. When doing this, we have found that the spindle rotation accuracy can vary drastically with rotational speed. The influence of bearing preload has a secondary importance. Comparison of the results of these studies has demonstrated adequacy of the models developed to the real spindle units.

Research Progress of Key Technology of High-Speed and High Precision Motorized Spindles

High speed machining and high precision machining are two tendencies of themanufacturing technology worldwide. The motorized spindle is the core component of the machine toolsfor achieving the high speed and high precise machining, which affects the general developmentlevel of the machine tools to a great extent. Progress of the key techniques is reviewed in thispaper, in which the high speed and high precision spindle bearings, the dynamical and thermalcharacteristics of spindles, the design technique of the high frequency motors and the drivers, theanti-electromagnetic damage technique of the motors, and the machining and assembling technique areinvolved. Finally, tha development tendencies of the motorized spindles are presented.

THE MORPHOLOGICAL CHANGES IN MUSCLE SPINDLES AND ALTERATIONS IN CELL ACTIVITY OF THE RATS' RED NUCLEUS AFTER 2 WEEKS' SIMULATED WEIGHTLESSNESS

Objective To study the morphological changes of soleus muscle spindle and electrical activity of neurons in Red Nucleus(RN) of the rat after 2 weeks' simulated weightlessness, and to reveal the interaction between proprioceptive inputs of muscle spindles and reciprocal alterations in RN under simulated weightlessness. Methods Twenty female rats were exposed to weightlessness simulated by tail-suspension for 14 days (SW-14d). Body weight(200-220g) matched female rats were control group(Con). The morphological changes in isolated muscle spindle of soleus muscle, the discharges of red nucleus neurons were observed after 14d tail-suspensions by silver staining and extracellular recording respectively. Results Compared with control group ,the nerve ending of muscle spindle in SW-14d was distorted, degenerated and dissolved; the diameters of intrafusal fibers and capsule in equatorial region of soleus muscle spindles were diminished(P<0.05). The spontaneous cell activity and discharge of RN neurons (spikes/s) induced by afferent firing from muscle spindles after injection of succinylcholine were reduced after 2 weeks' simulated weightlessness respectively (18.44±5.96 vs. 10.19±6.88, 32.50±8.08 vs. 16.86±5.97, P<0.01). Conclusion The degeneration of muscle spindle induced by simulated weightlessness may be one of the causes that led to alterations in discharges of RN.

Presence of Meiotic Spindles Indicates Early Cleavage of Embryos

Objective To assess whether the detection of the meiotic spindle could anticipate the appearance of early cleavage. Methods Oocytes were obtained from stimulated ovaries of consenting patients undergoing oocytes retrieval for ICSI. Spindles were imaged with the Polscope. After ICSI, oocytes with or without spindles were cultured for examination of early cleavage and embryo development. A total of 328 oocytes from 50 cycles were examined with the Polscope and inseminated by ICSI. Results Spindles were imaged in 81.7% of oocytes. After ICSI, more oocytes with spindles （78.4%） fertilized normally than oocytes without spindles （53.3%） （P〈0. 001）. At 25-27 h post ICSI, more fertilized oocytes developed from oocytes with spindles （81.9%） were detected early cleavage than those from oocytes without spindles （28.1%） （P〈0.001）. Significantly more embryos with early cleavage （82.2%） developed to high quality embryos at d 3 compared with the embryos without early cleavage （48.3%） （P=0.001）. The value of rs related to the relationship between spindles and early cleavage was 0.420 （P〈0.001）. Conclusion The existing of the early cleavage may have a predictive value on the opportunity of high quality embryos and the existing of the spindle may have a predictive value in the appearance of early cleavage.

AN OPTIMAL DESIGN OF RING SPINNING SPINDLES USING PROGRAM SAP84

In this paper, natural frequencies and vibration modes of spindl D1203 are calculated by us-ing structural analysis program SAP84. It is found that the second natural frequency of D1203spindle is too close to the range of working speed. In order to raise the second natural frequencyand to reduce the vibration noise, simple optimal design of several structural parameters are alsodiscussed by means of the orthogonal design method. It is shown that the better design is toshorten the length of the spindle blade appropriately and to increase the elasticity of its uppersupport.

The Application of Visual Organization Principle in the Detection of Sleep Spindles

In order to detect the sleep spindles simply and efficiently, a novel time-domain approach to detect sleep spindles based on the principles of visual organization is proposed. The code idea of the visual organization is to organize the primary visual elements according to some rules of organization, and to form a more meaningful object of visual processing, as the input of next process. After the collected EEG is processed with the merging algorithm based on the principle of visual organization, it can extract the time-domain feature frequency and duration time better. Use these features with a simple algorithm to detect spindles achieving sensitivity of 92.5% and specificity of 98.1%, which verifies the validity of this method to detect the sleep spindles.

Sleep spindles detection from human sleep EEG signals using autoregressive (AR) model: a surrogate data approach

A new algorithm for the detection of sleep spindles from human sleep EEG with surrogate data approach is presented. Surrogate data ap-proach is the state of the art technique for nonlinear spectral analysis. In this paper, by developing autoregressive (AR) models on short segment of the EEG is described as a superposition of harmonic oscillating with damping and frequency in time. Sleep spindle events are detected, whenever the damping of one or more frequencies falls below a prede-fined threshold. Based on a surrogate data, a method was proposed to test the hypothesis that the original data were generated by a linear Gaussian process. This method was tested on human sleep EEG signal. The algorithm work well for the detection of sleep spindles and in addition the analysis reveals the alpha and beta band activities in EEG. The rigorous statistical framework proves essential in establishing these results.

The Development of Hi-Speed Punching System Using A Couple of Rotating Bodies

Punched steel sheets (metal sheets or foils) as thi n as 0.1mm are quite useful in the field of filters and various precision instrume nts. Thus, we have to develop more accurate and speedy techniques for punching t hin sheets. The traditional punching method uses an up-down pressing motion of a punch or a die on a strip of metal. The efficiency of this method is determine d by the speed of the motion. In the case of punching a sequence of tiny holes w ith a few millimeters’ interval, the speed of feeding a strip of metal to the p unching machine cannot exceed only a couple of meters per minute. We have de veloped a new technique for punching tiny holes with a pair of rotating bodies i n order to increase the feeding speed up to 100 meters per minute. Our proposed technique is shown in Fig.1 where the female tool has a round blade and the male tool has an M-shape boss. In addition, the setting of two tools i s alternating. The interference between them cannot occur because the clearance between the front and the back edge of the male tool and the female tool in the rotating direction becomes infinite in this configuration. An appropriate cleara nce is given for the thickness of the sheet between the side edge of the male to ol and the female tool. The punching itself is done by shearing. The side edge o f the male tool does contact with the female tool, but they cannot be interferin g. Our technique has another advantage to the traditional up-down pressing mach ine where the stamped out chips are hard to be discharged. It is quite easy in o ur proposed technique. Fig.2, 3 show a sample of punched material [TPP116A,+39mm88mm,Y,PZ#]Fig.1 The configuration of the punching parts using the sequential punching system.[TPP116B,+43mm155mm,X,BP#]Fig.2 A sample of punched material using the continuous punch ing lineFig.3 A exterior picture of a piece of punched steel foil(coi l) using the continuous punching For our developed high speed punching system, it is shown for (1) the configurat ion of punching tool and the punching mechanism, (2) the influence of male shape on punched hole quality, (3) the outline of continuous punching system, (4) the relation between punching speed and accuracy of hole pitch and hole dimensi on, (5) the mechanical property of punched metal sheet and (6) capability of hig her punching.

Myocardial metastasis from ZEB1-and TWIST-positive spindle cell carcinoma of the esophagus:A case report

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.

Micro-and nano-scale spindle perpendicularity modulation method to enhance the quality of milled surfaces

Significant advancements in ultra-precision machining technology have forced a re-examination of the spindle perpendicularity errors'impact on the milled surface quality at the micro-nano scale.In this paper,a method of spindle precision adjustment is proposed to enhance surface finish quality.Sensitive errors in the machining process are identified using multi-body kinematic theory,with the milling process serving as an example.A two-degree-of-freedom(2-DOF)rotation platform is designed,optimized,and fabricated.The platform's static model is established based on elastic beam theory and verified by finite element analysis.Structural parameters are optimized via the response surface method in combination with the Pareto front.Experimental results reveal the effects of spindle speed,voltage amplitude,vibration frequency,cutting depth,and feed rate on the platform's modulation performance.The static modulation experiment shows that the perpendicularity error between the spindle and the guideway can be reduced from 92.5μrad to 0.25μrad.Finally,milling experiments show that the surface quality can be improved by 37.6%after spindle modulation.

Analysis of Dynamic Cross Response between Spindles in a Dual Spindle Type Multi-Functional Turning Machine

In order to meet increasing demand for higher productivity and flexibility, recently many kinds of multi-functional machine tools, which are capable of multiple machining functions or different kinds of machining processes on one machine, have been developed and widely used in manufacturing industries. In this study, a multi-functional turning lathe, which has two spindles and two turrets so that multiple turning operations and various machining processes could be performed simultaneously, has been developed. Furthermore, the equations of correlation between whole responses and cross responses of the two spindles have been derived to examine to what extent the two spindles affect each other’s vibrations.

基于Ansys workbench煤矿风机主轴有限元分析

煤矿风机在煤矿生产工作中起着重要的作用,风机主轴是风机的核心零件。针对风机主轴受到径向载荷和轴向载荷的影响是否会导致主轴损坏的问题,依据现实煤矿生产环境和条件,构建轴流式煤矿风机模型,对风机主轴进行静力学分析,根据主轴静力学分析中出现的主轴应力集中现象提出解决方案。对风机主轴进行优化设计,重新进行静力学分析,消除应力集中现象。采用模态分析法对风机主轴的强度性能和刚度性能进行检测,最后通过搭建试验平台对仿真结果进行验证。结果表明,当风机机主轴径向与轴向同时增加载荷时,风机主轴在工作过程中可安全可靠的运行。

Spindle-view系统在猪卵母细胞去核中的应用

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。

哺乳动物卵母细胞纺锤体组装机制的研究进展

哺乳动物卵母细胞减数分裂纺锤体的正常组装是确保减数分裂中染色体精确分离的关键。在细胞分裂过程中,将一整套染色体传递给子细胞对发育和组织稳态至关重要。双极纺锤体的组装异常通常会引起染色体错误分离,染色体分离错误又极容易导致自然流产以及染色体出生缺陷。因此,探究纺锤体组装机制对了解减数分裂进程是必需的。在体细胞中,有丝分裂纺锤体组装是由中心体充当微管组织中心介导。而哺乳动物卵母细胞中缺乏典型的中心体,依靠微管组织中心等其他途径来组装纺锤体。尽管有助于纺锤体组装的组分和途径有很多描述,但关于无中心体纺锤体的组装和功能机制仍有待完善。作者介绍了哺乳动物卵母细胞中无中心体纺锤体组装的过程,着重讲述了微管成核、纺锤体的双极化与伸长和染色体排列与分离涉及的分子机制,以及纺锤体检验点(SAC)在纺锤体组装中的作用机制。此外,还讨论了染色体与微丝在减数分裂过程中参与纺锤体组装作用机制,旨在为哺乳动物卵母细胞双极纺锤体组装及染色体分离机制的研究提供借鉴。