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 p...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.展开更多
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 prec...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.展开更多
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 rang...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.展开更多
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...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.展开更多
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 ...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.展开更多
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
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
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： Immunofluo...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.展开更多
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
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 unde...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.展开更多
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 retri...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.展开更多
Biphasic drug release is a popular advanced drug controlled release profle that has been drawing increasing attention from many felds.Electrospun nanofbers and their derivatives can be act as a strong platform for dev...Biphasic drug release is a popular advanced drug controlled release profle that has been drawing increasing attention from many felds.Electrospun nanofbers and their derivatives can be act as a strong platform for developing biphasic release dosage forms.In this study,a modifed coaxial electrospinning was implemented,in which little molecule solutions that contain a drug ibuprofen(IBU)and polyethylene glycol(PEG)were exploited as a sheath fuid to surround the core solutions composed of polymer ethyl cellulose(EC)and IBU.The prepared nanofber-based structural hybrids,i.e.,engineered spindles-on-astring(SOS)products,were successfully created and subjected to a series of characterizations.Scanning electron microscopy and transmission electron microscopy results showed the engineered SOS structures.IBU and the carriers EC and PEG had good compatibility,as suggested by X-ray difraction and Fourier transform infrared spectroscopy assessments.In vitro dissolution tests verifed that the SOS products were able to provide a typical biphasic release profle,releasing 40%of the loaded IBU within 1 h in an immediate manner in the frst phase,and the rest of the IBU in a sustained manner in the second phase.A combined mechanism of erosion and difusion is proposed for manipulating the IBU molecule release behaviors.展开更多
In 2024,global shipments of new short-staple spindles and open-end rotors decreased by 40%and 39%,respectively(year-on-year).Deliveries of long-staple spindles increased by 62%.The number of draw texturing spindles im...In 2024,global shipments of new short-staple spindles and open-end rotors decreased by 40%and 39%,respectively(year-on-year).Deliveries of long-staple spindles increased by 62%.The number of draw texturing spindles improved by 77%and shipped shuttleless looms grew by 32%.Shipments of large circular knitting machines deteriorated by 15%and shipped flat knitting machines registered a 16%increase.The sum of all deliveries in the fin-ishing segment slightlyrose by 6%.展开更多
Most hard disk spindles currently used are supported by grease lubricated deep-groove ball bearings.However, in the trend of increasing spindle speed and reducing size and cost, the shortcomings of ball bearing spin-d...Most hard disk spindles currently used are supported by grease lubricated deep-groove ball bearings.However, in the trend of increasing spindle speed and reducing size and cost, the shortcomings of ball bearing spin-dles, such as high non-repeatable run out, high acoustic noise and short life time at high running speed, make themunsuitable for high performance hard disk drives (HDD). On the contrary, the dynamic characteristics of hydrody-namic bearing spindles are superior to that of ball bearing spindles. Therefore, they are considered to be the substi-tute of ball bearing spindles in HDD. In this paper, a simulative setup of HDD is build up. The dynamic characteristicsof liquid lubricated spiral groove bearing(SGB) spindles are studied. The effects of both operating condition andbearing clearance are investigated. It is found that running speed of the spindle has significant influence on its dy-namic performance, while the load has little influence. The effect of clearance is also evident.展开更多
Background:The perception of effort is a key determinant of endurance performance and a barrier to physical activity in inactive populations.From a neurophysiological viewpoint,effort perception is thought to arise fr...Background:The perception of effort is a key determinant of endurance performance and a barrier to physical activity in inactive populations.From a neurophysiological viewpoint,effort perception is thought to arise from the brain processing of an efference copy of the motor command in sensory areas.However,recent research suggests that feedback from muscle spindles plays a significant role in this perception.In this study,tendon vibration protocols were employed to attenuate sensory feedback during subsequent cycling exercises.The aim was to assess whether vibration would increase cycling power output,muscle activation,and heart rate at fixed perceived effort intensities.Methods:Fifteen healthy young participants completed 2 experimental visits(vibration and sham).In each visit,participants performed two 3-min cycling bouts,1 at a moderate perceived effort intensity and 1 at a strong perceived effort intensity,before(pre)and after(post)an actual or a sham vibration protocol.Vibration was applied bilaterally on the patellar and Achilles tendons for 10 min.Power output,heart rate,and vastus lateralis electromyography(VL EMG)were recorded and averaged for each bout.Absolute values as well as relative change(%)between pre and post conditions were compared across sham and vibration conditions.Results:At moderate perceived effort,power output,heart rate,and VL EMG increased post-vibration compared to pre-vibration(p<0.05),while no difference was observed in the sham condition.At strong perceived effort,power output and VL EMG decreased post-sham(p<0.05)but remained unchanged post-vibration.Moreover,the relative change between pre and post conditions was significantly higher in the vibration conditions compared to the sham condition for all variables.Conclusion:This study shows that tendon vibration reduces effort perception during subsequent cycling bouts.This effect is likely a consequence of vibration-induced reduction in muscle spindle reafferent signaling to the brain,but this mechanism remains to be further elucidated.From an applied perspective,these findings highlight tendon vibration as a promising tool for enhancing physical activity engagement.展开更多
After the third prezygotic division during conjugation of Paramecium caudatum,migratory and stationary pronuclei are produced.The migratory pronuclei remain in the paroral region tightly against the conjugating bounda...After the third prezygotic division during conjugation of Paramecium caudatum,migratory and stationary pronuclei are produced.The migratory pronuclei remain in the paroral region tightly against the conjugating boundaries;while the stationary pronuclei are located beside the migratory pronuclei.To date,however,it is not clear what causes this close side-by-side localization between migratory and stationary pronuclei.In the current study,immunofluorescence staining with monoclonal antibody of anti-α tubulin indicated that ＂U＂ or ＂V＂ shaped spindles connected the migratory and stationary pronuclei during the third prezygotic division.This observation accounts for the close localization between these two types of pronuclei.展开更多
During conjugation of Paramecium caudatum, nuclear events occur in a scheduled program. Morphological studies on nuclear behavior during conjugation of P. caudatum have been performed since the end of the 19th century...During conjugation of Paramecium caudatum, nuclear events occur in a scheduled program. Morphological studies on nuclear behavior during conjugation of P. caudatum have been performed since the end of the 19th century. Here we report on new details concerning the conjugation of P. caudatum through the staining of conjugating ceils with protargol, carbol fuchsin solution, Hoechst 33342 and immunofluorescence labeling with monoclonal antibody of anti-a tubulin. 1） The crescent nucleus is a characteristic of the meiotic prophase of P. caudatum, has an unstained area. We stained this area with protargol, which was separated from the chromatin area and was not detected by the other stainings. 2） In regards to the four meiotic products, it has long been considered that only one product enters the paroral cone region （PC） and survives after meiosis. However, our protargol and immunofluorescence labeling results indicated that PC entrance of the meiotic product happened before the completion of meiosis instead of after. 3） In our previous study, protargol staining indicated the presence of a swollen structure around the central part of the ＂U＂ and ＂V＂ shaped spindles connecting the two types of prospective pronuclei. However, immunofluorescence labeling with anti-a tubulin antibodies gave a different image from protargol. All these observations form the basis for further studies of their molecular mechanisms.展开更多
In the machining of high-end optical components,the aerostatic spindle error of an ultra-precision machine tool has a significant impact on the surface quality of the machined surfaces.The surfaces of many high-end op...In the machining of high-end optical components,the aerostatic spindle error of an ultra-precision machine tool has a significant impact on the surface quality of the machined surfaces.The surfaces of many high-end optical components need to meet the extremely stringent requirements of the full-frequency band error,which poses significant challenge to the control of the aerostatic spindle error.In this research,we put forward an active control method for the frequency domain error of the aerostatic spindle based on acoustic levitation,in which the acousticmagnetism-fluid-solid multi-field coupling rotor dynamics modeling method of the aerostatic spindle was proposed and the corresponding multi-field coupling model was established.Through the numerical simulation and preliminary experiments,the influence law of acoustic levitation on the frequency domain error of the aerostatic spindle is obtained.The results showed that acoustic levitation can be used to control the frequency domain error of the aerostatic spindle to some extent,which verified the effectiveness of the proposed method.展开更多
BACKGROUND Hepatitis B virus(HBV)infection is a leading cause of global hepatocellular carcinoma(HCC).Conventional biomarkers such as alpha-fetoprotein(AFP)demonstrate suboptimal sensitivity and specificity.Emerging e...BACKGROUND Hepatitis B virus(HBV)infection is a leading cause of global hepatocellular carcinoma(HCC).Conventional biomarkers such as alpha-fetoprotein(AFP)demonstrate suboptimal sensitivity and specificity.Emerging evidence suggests that serum extra spindle pole bodies like 1(ESPL1)protein and p53 antibody may improve diagnostic accuracy.AIM To assess and compare the diagnostic performance of serum ESPL1 protein and p53 antibody in HBV-related HCC(HBV-HCC).METHODS This case-control study from the First Affiliated Hospital of Guangxi Medical University enrolled 30 patients with chronic hepatitis B(CHB),30 with HBV-related liver cirrhosis(HBV-LC),55 with HBV-HCC,and 30 healthy controls.Serum ESPL1 protein and p53 antibody levels were quantified via ELISA.Diagnostic performance was evaluated using receiver operating characteristic(ROC)curve analysis,including sensitivity,specificity,and correlation with AFP.RESULTS Serum ESPL1 protein levels progressively increased across disease stages(CHB:89.9 ng/L;HBV-LC:188.83 ng/L;HBV-HCC:317.63 ng/L),with a significantly higher area under the ROC curve(AUC=0.917)than either p53 antibody(AUC=0.725)or AFP(AUC=0.678).p53 antibody levels were significantly elevated only in the HBVHCC group.ESPL1 demonstrated superior sensitivity and concordance with histopathological findings.A significant correlation between ESPL1 and p53 antibody levels was observed exclusively in the HBV-HCC group(r=0.320,P=0.017),suggesting potential interplay in malignant transformation.CONCLUSION Serum ESPL1 protein,a promising biomarker for early HBV-HCC detection,outperforms p53 antibody in diagnostic reliability.Higher ESPL1 levels correlate with increased HCC risk in chronic HBV patients.展开更多
文摘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.
文摘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.
文摘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.
基金This project was supported by the National Natural Science Foundation of China (No.30300106)
文摘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.
文摘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.
文摘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.
基金supported by the Medical Science and Technology Innovation Foundation of Nanjing Military Area Command of Chinese PLA in 2013,ZX22
文摘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.
基金Supported by National Natural Science Foundation of China, No. 30340036 and 30470891 Startup Grant from Jiangsu University, and Grant of Zhenjiang Key Institute of Clinical Laboratory Medicine (SH2006066)
文摘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.
文摘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.
文摘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.
文摘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.
基金The study is fnancially supported by the Medical Engineering Cross Project between University of Shanghai for Science&Technology and Navy Military Medical University(No.2020201)the Natural Science Foundation of Shanghai(No.20ZR1439000)the National Natural Science Foundation of China(No.51803121),and Projects 2019-YH-15 and 21QNPY062.
文摘Biphasic drug release is a popular advanced drug controlled release profle that has been drawing increasing attention from many felds.Electrospun nanofbers and their derivatives can be act as a strong platform for developing biphasic release dosage forms.In this study,a modifed coaxial electrospinning was implemented,in which little molecule solutions that contain a drug ibuprofen(IBU)and polyethylene glycol(PEG)were exploited as a sheath fuid to surround the core solutions composed of polymer ethyl cellulose(EC)and IBU.The prepared nanofber-based structural hybrids,i.e.,engineered spindles-on-astring(SOS)products,were successfully created and subjected to a series of characterizations.Scanning electron microscopy and transmission electron microscopy results showed the engineered SOS structures.IBU and the carriers EC and PEG had good compatibility,as suggested by X-ray difraction and Fourier transform infrared spectroscopy assessments.In vitro dissolution tests verifed that the SOS products were able to provide a typical biphasic release profle,releasing 40%of the loaded IBU within 1 h in an immediate manner in the frst phase,and the rest of the IBU in a sustained manner in the second phase.A combined mechanism of erosion and difusion is proposed for manipulating the IBU molecule release behaviors.
文摘In 2024,global shipments of new short-staple spindles and open-end rotors decreased by 40%and 39%,respectively(year-on-year).Deliveries of long-staple spindles increased by 62%.The number of draw texturing spindles improved by 77%and shipped shuttleless looms grew by 32%.Shipments of large circular knitting machines deteriorated by 15%and shipped flat knitting machines registered a 16%increase.The sum of all deliveries in the fin-ishing segment slightlyrose by 6%.
文摘Most hard disk spindles currently used are supported by grease lubricated deep-groove ball bearings.However, in the trend of increasing spindle speed and reducing size and cost, the shortcomings of ball bearing spin-dles, such as high non-repeatable run out, high acoustic noise and short life time at high running speed, make themunsuitable for high performance hard disk drives (HDD). On the contrary, the dynamic characteristics of hydrody-namic bearing spindles are superior to that of ball bearing spindles. Therefore, they are considered to be the substi-tute of ball bearing spindles in HDD. In this paper, a simulative setup of HDD is build up. The dynamic characteristicsof liquid lubricated spiral groove bearing(SGB) spindles are studied. The effects of both operating condition andbearing clearance are investigated. It is found that running speed of the spindle has significant influence on its dy-namic performance, while the load has little influence. The effect of clearance is also evident.
基金supported by the French National Research Agency(Agence Nationale de la Recherche,ANR,Grant No.ANR-23-CE37-0014)for the Effort_(LESS)Project.
文摘Background:The perception of effort is a key determinant of endurance performance and a barrier to physical activity in inactive populations.From a neurophysiological viewpoint,effort perception is thought to arise from the brain processing of an efference copy of the motor command in sensory areas.However,recent research suggests that feedback from muscle spindles plays a significant role in this perception.In this study,tendon vibration protocols were employed to attenuate sensory feedback during subsequent cycling exercises.The aim was to assess whether vibration would increase cycling power output,muscle activation,and heart rate at fixed perceived effort intensities.Methods:Fifteen healthy young participants completed 2 experimental visits(vibration and sham).In each visit,participants performed two 3-min cycling bouts,1 at a moderate perceived effort intensity and 1 at a strong perceived effort intensity,before(pre)and after(post)an actual or a sham vibration protocol.Vibration was applied bilaterally on the patellar and Achilles tendons for 10 min.Power output,heart rate,and vastus lateralis electromyography(VL EMG)were recorded and averaged for each bout.Absolute values as well as relative change(%)between pre and post conditions were compared across sham and vibration conditions.Results:At moderate perceived effort,power output,heart rate,and VL EMG increased post-vibration compared to pre-vibration(p<0.05),while no difference was observed in the sham condition.At strong perceived effort,power output and VL EMG decreased post-sham(p<0.05)but remained unchanged post-vibration.Moreover,the relative change between pre and post conditions was significantly higher in the vibration conditions compared to the sham condition for all variables.Conclusion:This study shows that tendon vibration reduces effort perception during subsequent cycling bouts.This effect is likely a consequence of vibration-induced reduction in muscle spindle reafferent signaling to the brain,but this mechanism remains to be further elucidated.From an applied perspective,these findings highlight tendon vibration as a promising tool for enhancing physical activity engagement.
文摘After the third prezygotic division during conjugation of Paramecium caudatum,migratory and stationary pronuclei are produced.The migratory pronuclei remain in the paroral region tightly against the conjugating boundaries;while the stationary pronuclei are located beside the migratory pronuclei.To date,however,it is not clear what causes this close side-by-side localization between migratory and stationary pronuclei.In the current study,immunofluorescence staining with monoclonal antibody of anti-α tubulin indicated that ＂U＂ or ＂V＂ shaped spindles connected the migratory and stationary pronuclei during the third prezygotic division.This observation accounts for the close localization between these two types of pronuclei.
文摘During conjugation of Paramecium caudatum, nuclear events occur in a scheduled program. Morphological studies on nuclear behavior during conjugation of P. caudatum have been performed since the end of the 19th century. Here we report on new details concerning the conjugation of P. caudatum through the staining of conjugating ceils with protargol, carbol fuchsin solution, Hoechst 33342 and immunofluorescence labeling with monoclonal antibody of anti-a tubulin. 1） The crescent nucleus is a characteristic of the meiotic prophase of P. caudatum, has an unstained area. We stained this area with protargol, which was separated from the chromatin area and was not detected by the other stainings. 2） In regards to the four meiotic products, it has long been considered that only one product enters the paroral cone region （PC） and survives after meiosis. However, our protargol and immunofluorescence labeling results indicated that PC entrance of the meiotic product happened before the completion of meiosis instead of after. 3） In our previous study, protargol staining indicated the presence of a swollen structure around the central part of the ＂U＂ and ＂V＂ shaped spindles connecting the two types of prospective pronuclei. However, immunofluorescence labeling with anti-a tubulin antibodies gave a different image from protargol. All these observations form the basis for further studies of their molecular mechanisms.
基金Supported by National Natural Science Foundation of China(Grant No.52475494)Zhejiang Provincial Natural Science Foundation of China(Grant No.LY22E050003)Fundamental Research Funds for the Provincial Universities of Zhejiang(Grant No.RF-A2020005).
文摘In the machining of high-end optical components,the aerostatic spindle error of an ultra-precision machine tool has a significant impact on the surface quality of the machined surfaces.The surfaces of many high-end optical components need to meet the extremely stringent requirements of the full-frequency band error,which poses significant challenge to the control of the aerostatic spindle error.In this research,we put forward an active control method for the frequency domain error of the aerostatic spindle based on acoustic levitation,in which the acousticmagnetism-fluid-solid multi-field coupling rotor dynamics modeling method of the aerostatic spindle was proposed and the corresponding multi-field coupling model was established.Through the numerical simulation and preliminary experiments,the influence law of acoustic levitation on the frequency domain error of the aerostatic spindle is obtained.The results showed that acoustic levitation can be used to control the frequency domain error of the aerostatic spindle to some extent,which verified the effectiveness of the proposed method.
基金Supported by National Natural Science Foundation of China,No.81960115,No.82160123 and No.82260124Key Laboratory of Early Prevention and Treatment for Regional High Frequency Tumor(Guangxi Medical University),Ministry of Education,No.GKEZZ202107+1 种基金Guangxi Key Laboratory of Early Prevention and Treatment for Regional High Frequency Tumor,No.GKE-ZZ202218Guangxi Science and Technology Program,No.AD25069077.
文摘BACKGROUND Hepatitis B virus(HBV)infection is a leading cause of global hepatocellular carcinoma(HCC).Conventional biomarkers such as alpha-fetoprotein(AFP)demonstrate suboptimal sensitivity and specificity.Emerging evidence suggests that serum extra spindle pole bodies like 1(ESPL1)protein and p53 antibody may improve diagnostic accuracy.AIM To assess and compare the diagnostic performance of serum ESPL1 protein and p53 antibody in HBV-related HCC(HBV-HCC).METHODS This case-control study from the First Affiliated Hospital of Guangxi Medical University enrolled 30 patients with chronic hepatitis B(CHB),30 with HBV-related liver cirrhosis(HBV-LC),55 with HBV-HCC,and 30 healthy controls.Serum ESPL1 protein and p53 antibody levels were quantified via ELISA.Diagnostic performance was evaluated using receiver operating characteristic(ROC)curve analysis,including sensitivity,specificity,and correlation with AFP.RESULTS Serum ESPL1 protein levels progressively increased across disease stages(CHB:89.9 ng/L;HBV-LC:188.83 ng/L;HBV-HCC:317.63 ng/L),with a significantly higher area under the ROC curve(AUC=0.917)than either p53 antibody(AUC=0.725)or AFP(AUC=0.678).p53 antibody levels were significantly elevated only in the HBVHCC group.ESPL1 demonstrated superior sensitivity and concordance with histopathological findings.A significant correlation between ESPL1 and p53 antibody levels was observed exclusively in the HBV-HCC group(r=0.320,P=0.017),suggesting potential interplay in malignant transformation.CONCLUSION Serum ESPL1 protein,a promising biomarker for early HBV-HCC detection,outperforms p53 antibody in diagnostic reliability.Higher ESPL1 levels correlate with increased HCC risk in chronic HBV patients.
