A miniature short stroke tubular linear actuator and its control

Miniature actuators are the critical components in the robotic applications with high intelligence, high mobility and small scales. Among various types of actuators, linear actuators show advantages in many aspects. A miniature short stroke PM tubular linear actuator for the micro robotic applications is presented in this paper. The actuator is deliberately designed based on the optimal force capability and a proper sensorless control scheme is developed for the driving of the actuator. Experiment both on the prototype of the actuator and the drive system show the validity of the design

A semiparametric likelihood-based method for regression analysis of mixed panel-count data

Panel-count data arise when each study subject is observed only at discrete time points in a recurrent event study, and only the numbers of the event of interest between observation time points are recorded (Sun and Zhao, 2013). However, sometimes the exact number of events between some observation times is unknown and what we know is only whether the event of interest has occurred. In this article, we will refer this type of data to as mixed panel-count data and propose a likelihood-based semiparametric regression method for their analysis by using the nonhomogeneous Poisson process assumption. However, we establish the asymptotic properties of the resulting estimator by employing the empirical process theory and without using the Poisson assumption. Also, we conduct an extensive simulation study, which suggests that the proposed method works well in practice. Finally, the method is applied to a Childhood Cancer Survivor Study that motivated this study

Role of spinal cord glutamate transporter during normal sensory transmission and pathological pain states

Glutamate is a neurotransmitter critical for spinal excitatory synaptic transmission and for generation and maintenance of spinal states of pain hypersensitivity via activation of glutamate receptors. Understanding the regulation of synaptically and non-synaptically released glutamate associated with pathological pain is important in exploring novel molecular mechanisms and developing therapeutic strategies of pathological pain. The glutamate transporter system is the primary mechanism for the inactivation of synaptically released glutamate and the maintenance of glutamate homeostasis. Recent studies demonstrated that spinal glutamate transporter inhibition relieved pathological pain, suggesting that the spinal glutamate transporter might serve as a therapeutic target for treatment of pathological pain. However, the exact function of glutamate transporter in pathological pain is not completely understood. This report will review the evidence for the role of the spinal glutamate transporter during normal sensory transmission and pathological pain conditions and discuss potential mechanisms by which spinal glutamate transporter is involved in pathological pain

Influence of Silicon on Thermal Conductivity at Room Temperature of Al–Si–Fe Alloys

The analysis of densities and thermal conductivities has been performed for cast experimentally made aluminum alloys containing different content of silicon starting from 0% to 12% (mass%). All alloys have been additionally supplemented by iron up to 1% mass for better casting properties. Results have shown a strong tendency of decrease in the thermal conductivity with increasing silicon content. The same character is found for densities behavior. Keywords: aluminum-silicon alloys, thermal conductivity, heat exchange, iron, cast alloys, structure, temperatur

Influence of Silicon on Temperature Dependence of Thermal Conductivity of Al–Si–Fe Alloys

Temperature dependence analysis of thermal conductivity was carried out for series of aluminum alloys with 1% Fe (mass%) and different content of silicon starting from 0% to 6% (mass%). It is shown that the best alloy for heat exchange applications is alloy with 4% of silicon (mass%). Temperature dependence of thermal conductivity shows the strong decreasing character for silicon-alloyed samples in comparison to pure aluminum. Keywords: aluminum–silicon alloys, thermal conductivity, heat exchange, iron, cast alloys, structure, temperatur

Three-dimensional topological structures and formation processes of dislocations in Au nanowire under tension loading

Dislocation is an important microstructural configuration in most crystalline materials, but it is still difficult for experiments to detect its local atomic structures and formation processes. Molecular dynamics simulation provides a powerful tool to investigate the dislocation by means of some geometrical structural analysis methods, but most of these methods cannot accurately distinguish the nuances of local configurations. Herein, we propose a new microstructural analysis method of cluster-type-index method (CTIM). The three-dimensional (3D) topological structures and formation processes of dislocations during tensioning Au nanowire are illuminated by means of CTIM. It is found that the favourite local atomic structures in dislocations are the defective FCC clusters represented by the CTIM indexes (13, 3/1421 2/1431 2/1441 4/1541 2/1661). The vector analysis method based on the accumulation of lattice distortions cannot identified the aggregation of disordered atoms in the initial nucleation of dislocation. In the formation processes of dislocation atoms, three trajectories of T1: FCC→(13, 3/1421 2/1431 2/1441 4/1541 2/1661), T2: FCC→(12, 2/1311 1/1411 9/1421) and T3: FCC→(11, 4/1311 7/1421) are favorite. The dislocation atoms following the T1 trajectory are mainly located at the core of dislocations, while that following the T2 and T3 trajectories is at the front of dislocations. CTIM would provide an effective tool to investigate the defective structures and their interactions in nanocrystalline structures

CO2 dissociation activated through electron attachment on reduced rutile TiO2(110)-1x1 surface

Converting CO$_2$ to useful compounds through the solar photocatalytic reduction has been one of the most promising strategies for artificial carbon recycling. The highly relevant photocatalytic substrate for CO$_2$ conversion has been the popular TiO$_2$ surfaces. However, the lack of accurate fundamental parameters that determine the CO$_2$ reduction on TiO$_2$ has limited our ability to control these complicated photocatalysis processes. We have systematically studied the reduction of CO2 at specific sites of the rutile TiO$_2$(110)-1x1 surface using scanning tunneling microscopy at 80 K. The dissociation of CO2 molecules is found to be activated by one electron attachment process and its energy threshold, corresponding to the CO$_2^{\dot-}$/CO$_2$ redox potential, is unambiguously determined to be 2.3 eV higher than the onset of the TiO$_2$ conduction band. The dissociation rate as a function of electron injection energy is also provided. Such information can be used as practical guidelines for the design of effective catalysts for CO$_2$ photoreduction

Myocyte-Specific Overexpressing HDAC4 Promotes Myocardial Ischemia/Reperfusion Injury

Background: Histone deacetylases (HDACs) play a critical role in modulating myocardial protection and cardiomyocyte survivals. However, Specific HDAC isoforms in mediating myocardial ischemia/reperfusion injury remain currently unknown. We used cardiomyocyte-specific overexpression of active HDAC4 to determine the functional role of activated HDAC4 in regulating myocardial ischemia and reperfusion in isovolumetric perfused hearts. Methods: In this study, we created myocyte-specific active HDAC4 transgenic mice to examine the functional role of active HDAC4 in mediating myocardial I/R injury. Ventricular function was determined in the isovolumetric heart, and infarct size was determined using tetrazolium chloride staining. Results: Myocyte-specific overexpressing activated HDAC4 in mice promoted myocardial I/R injury, as indicated by the increases in infarct size and reduction of ventricular functional recovery following I/R injury. Notably, active HDAC4 overexpression led to an increase in LC-3 and active caspase 3 and decrease in SOD-1 in myocardium. Delivery of chemical HDAC inhibitor attenuated the detrimental effects of active HDAC4 on I/R injury, revealing the pivotal role of active HDAC4 in response to myocardial I/R injury. Conclusions: Taken together, these findings are the first to define that activated HDAC4 as a crucial regulator for myocardial ischemia and reperfusion injury

Image-driven unsupervised 3D model co-segmentation

Segmentation of 3D models is a fundamental task in computer graphics and vision. Geometric methods usually lead to non-semantic and fragmentary segmentations. Learning techniques require a large amount of labeled training data. In this paper, we explore the feasibility of 3D model segmentation by taking advantage of the huge number of easy-to-obtain 2D realistic images available on the Internet. The regional color exhibited in images provides information that is valuable for segmentation. To transfer the segmentations, we first filter out inappropriate images with several criteria. The views of these images are estimated by our proposed texture-invariant view estimation Siamese network. The training samples are generated by rendering-based synthesis without laborious labeling. Subsequently, we transfer and merge the segmentations produced by each individual image by applying registration and a graph-based aggregation strategy. The final result is obtained by combining all segmentations within the 3D model set. Our qualitative and quantitative experimental results on several model categories validate effectiveness of our proposed method