43 research outputs found
ERK MAP kinase activation in spinal cord regulates phosphorylation of Cdk5 at serine 159 and contributes to peripheral inflammation induced pain/hypersensitivity.
Cyclin-dependent kinase 5 is a proline-directed serine/threonine kinase and its activity participates in the regulation of nociceptive signaling. Like binding with the activators (P35 or P25), the phosphorylation of Cdk5 plays a critical role in Cdk5 activation. However, it is still unclear whether Cdk5 phosphorylation (p-Cdk5) contributes to pain hyperalgesia. The aim of our current study was to identify the roles of p-Cdk5 and its upstream regulator in response to peripheral inflammation. Complete Freund's adjuvant (CFA) injection induced acute peripheral inflammation and heat hyperalgesia, which was accompanied by sustained increases in phospho-ERK1/2 (p-ERK1/2) and phospho-Cdk5(S159) (p-Cdk5(S159)) in the spinal cord dorsal horn (SCDH). CFA-induced p-ERK primarily colocalized with p-Cdk5(S159) in superficial dorsal horn neurons. Levels in p-ERK and p-Cdk5 were also increased in the 2(nd) phase of hyperalgesia induced by formalin injection, which can produce acute and tonic inflammatory pain. MAP kinase kinase inhibitor U0126 intrathecal delivery significantly suppressed the elevation of p-Cdk5(S159), Cdk5 activity and pain response behavior (Heat hyperalgesia, Spontaneous flinches) induced by CFA or formalin injection. Cdk5 inhibitor roscovitine intrathecal administration also suppressed CFA-induced heat hyperalgesia and Cdk5 phosphorylation, but did not attenuate ERK activation. All these findings suggested that p-Cdk5(S159) regulated by ERK pathway activity may be a critical mechanism involved in the activation of Cdk5 in nociceptive spinal neurons contributes to peripheral inflammatory pain hypersensitivity
Underwater High-Precision 3D Reconstruction System Based on Rotating Scanning
This paper presents an underwater high-precision line laser three-dimensional (3D) scanning (LLS) system with rotary scanning mode, which is composed of a low illumination underwater camera and a green line laser projector. The underwater 3D data acquisition can be realized in the range of field of view of 50° (vertical) × 360° (horizontal). We compensate the refraction of the 3D reconstruction system to reduce the angle error caused by the refraction of light on different media surfaces and reduce the impact of refraction on the image quality. In order to verify the reconstruction effect of the 3D reconstruction system and the effectiveness of the refraction compensation algorithm, we conducted error experiments on a standard sphere. The results show that the system’s underwater reconstruction error is less than 0.6 mm within the working distance of 140 mm~2500 mm, which meets the design requirements. It can provide reference for the development of low-cost underwater 3D laser scanning system
Active earth pressure on translating rigid retaining structures considering soil arching effect
Accurate determination of active earth pressure distribution on rigid retaining wall including the magnitude and height of application of its resultant is of immense importance for designing the earth retaining structures. In this paper, an analytical solution based on the soil arching effect is presented. According to Mohr\u27s stress circle, a new relationship between active earth pressure and normal stress on failure surface at any depth from backfill surface is obtained. By analysing parabolic arch of minor principal stresses, a new coefficient of active lateral earth pressure is proposed. The problems that the vertical static equilibrium equation of differential flat element considering soil arching effect is not reasonable are analysed. Then, based on the limit equilibrium of differential flat element, new formulas relevant to the distribution of active earth pressure, the magnitude and height of application of its resultant are derived. The effects of backfill internal friction angle, wall-soil friction angle, wall height, surcharge load and backfill unit weight on those formulas are investigated in detail. In addition, the comparisons of the predictions by proposed equations with available test data as well as existing solutions are carried out, which implies adequate accuracy of the proposed solutions for all ratios of wall-soil friction angle to internal friction angle
Role of <i>E. coli</i>-Secretion and Melamine in Selective Formation of CaC<sub>2</sub>O<sub>4</sub>·H<sub>2</sub>O and CaC<sub>2</sub>O<sub>4</sub>·2H<sub>2</sub>O Crystals
The influence of <i>Escherichia
coliform</i> secretion
(<i>E. coli</i>-secretion) and melamine on the crystallization
of calcium oxalate has been investigated in order to determine its
role in morphological control and the effects on the kinetics of the
calcium oxalate crystals. The crystals obtained were characterized
by scanning electron microscopy, Fourier-transform infrared spectroscopy,
X-ray powder diffraction, and thermal gravimetric analyzer. At the
same time, conductivity meter and zeta potentiometer have been used
to study the kinetic process of the crystal formation. The results
show that, in the absence of <i>E. coli</i>-secretion, calcium
oxalate monohydrate (COM) was obtained, which is the most stable crystal
form of calcium oxalate and the major component of urinary stones,
while in the presence of the secretion, the obtained crystals were
calcium oxalate dehydrate (COD) instead of COM. Simulation experiments
under artificial urine circumstance further demonstrated the drastic
effect of <i>E. coli</i>-secretion on the calcium oxalate
dihydrate crystal form. Furthermore, the acceleration effect of melamine
on the formation of stones was also studied. Additionally, a slight
influence of melamine on the crystallization of calcium oxalate has
been found for the first time. Thus, a method to inhibit stone has
been found and is expected to provide important data for the development
of the calculi treatment
Docosahexaenoic Acid Rescues Synaptogenesis Impairment and Long-Term Memory Deficits Caused by Postnatal Multiple Sevoflurane Exposures
Sevoflurane exposures were demonstrated to induce neurotoxicity in the developing brain in both human and animal studies. However, there is no effective approach to reverse it. The present study aimed to evaluate the feasibility of utilizing docosahexaenoic acid (DHA) to prevent sevoflurane-induced neurotoxicity. P6 (postnatal 6 days) mice were administrated DHA after exposure to 3% sevoflurane for two hours daily in three consecutive days. Molecular expressions of synaptic makers (PSD95, synaptophysin) and synaptic morphological changes were investigated by Western blot analysis and transmission electron microscopy, respectively. Meanwhile, Morris water maze test was used to assess spatial memory of mice at P31 (postnatal 31 days). DHA restored sevoflurane-induced decreased level of PSD95 and synaptophysin expressions and increased PSD areas and also improved long-term spatial memory. These results suggest that DHA could rescue synaptogenesis impairment and long-term memory deficits in postnatal caused by multiple sevoflurane exposures
Normal Physics Model of Aerial Remote Sensing Platform and Systemic Accuracy Assessment Variable Baseline-height Ratio
Accuracy is a key factor in high-resolution remote sensing and photogrammetry.The factors that affect accuracy are imaging system errors and data processing errors.Because of the complexity of aerial camera system errors,this paper focuses on the design of digital aerial camera system,to reduce the system error and provide data procession fundamentally.There are many kinds of digital aerial camera system at present,but lacking a unified physical model,which causes the system to be built in multi-camera and multi-rigid model.Such system is complex,costly,and difficult to describe,and is easily affected by factors such as vibration and temperature,so the installed accuracy can only reach millimeter level.For this reason,this paper proposes the unified physical structure of digital aerial camera,which imitates the theory of out-of-field multi-CCD,in-field multi-CCD,and once-imaging and twice-imaging digital camera systems.Considering this,the spatial-temporal representation of the variable baseline-height ratio is established.From the variable baseline-height ratio,we can link the opto-mechanical spatial parameters with the elevation accuracy,so that to achieve connection between the surface elevation with opto-mechanical structural parameter; further designing the twice-imaging digital camera prototype system and the wideband limb imaging spectrometer,which provides prototype for transformation from the current multi-rigid,one-time imaging aerial camera to single rigid structure.Our research has laid a theoretical foundation and prototype references for the construction and industrialization of digital aerial system