Microvessel changes in the gerbil hippocampus after cerebral ischemia and reperfusion by Buyang Huanwu decoction pretreatment

Buyang Huanwu decoction （BYHWD） is a classic recipe for the prevention and treatment of ischemic cerebrovascular disease. Gerbils were pretreated with BYHWD, and then subjected to cerebral ischemia and reperfusion. Microvascular changes were determined with laser Doppler monitoring, tannic acid-ferric chloride mordant, and electron microscopy. Results showed that BYHWD pretreatment could enhance the function of hippocampal microvessels, prevent injury, and increase microvasular density and microvasular area density. Thus, these results suggest that BYHWD pretreatment could prevent microvascular occlusion, enhance the capacity of microvascular reperfusion, increase cerebral blood flow, and inhibit neuronal damage, and may be an effective therapy against brain ischemic injury.

Effect of Buyanghuanwu Decoction on PI3K/AKT Signaling Pathway and Aquaporin AQP4 in Cerebral Hemorrhage Rats

[Objectives] To explore the effect of Buyanghuanwu decoction on PI3K/AKT signaling pathway and aquaporin AQP4 in cerebral hemorrhage rats and clarify the mechanism to provide clear direction and target for cerebral hemorrhage treatment caused by cerebral edema.[Methods]SD rats were randomly divided into six groups: model group,sham operation group,Buyanghuanwu decoction low,medium and high dose groups,and Ginkgo biloba group. Model group,Buyanghuanwu decoction group,G. biloba group were prepared to be intracerebral hemorrhage rat models by referring to Rosenberg law. While the expression of " polarity" of aquaporin AQP4 was detected by immunofluorescence labeling method,the Evans blue( Evans Blue,EB) content of brain tissue was determined by Spectrophotometry. In addition,the water content of brain tissue was detected by wet and dry weight method. [Results] When compared to the model group,the Buyang Huanwu decoction group,G. biloba group of PI3K and AKT proteins expression increased significantly( P < 0. 05) and AQP4 in Astrocyte end feet membrane concentrated expression significantly increased( P < 0. 05),EB content and water content of brain tissue significantly reduced( P <0. 05).[Conclusions]The protective mechanisms of Buyanghuanwu decoction on cerebral hemorrhage can work might because it can activate PI3K/AKT signaling pathway,regulate AQP4 " polar" expression,and reduce the permeability of the blood brain barrier and cerebral edema.

Optical response of an inverted InAs/GaSb quantum well in an in-plane magnetic field

The optical response of an inverted InAs/GaSb quantum well is studied theoretically. The influence of an in-plane magnetic field that is applied parallel to the quantum well is considered. This in-plane magnetic field will induce a dynamical polarization even when the electric field component of the external optical field is parallel to the quantum well.The electron-electron interaction in the quantum well system will lead to the de-polarization effect. This effect is found to be important and is taken into account in the calculation of the optical response. It is found that the main feature in the frequency dependence of the velocity-velocity correlation function remains when the velocity considered is parallel to the in-plane magnetic field. When the direction of the velocity is perpendicular to the in-plane magnetic field, the depolarization effect will suppress the oscillatory behavior in the corresponding velocity-velocity correlation function. The in-plane magnetic field can change the band structure of the quantum well drastically from a gapped semiconductor to a no-gapped semi-metal, but it is found that the distribution of the velocity matrix elements or the optical transition matrix elements in the wave vector space has the same two-tadpole topology.

Study on the Expression of Dopamine Receptor-3(DRD3) in Rats after Sacral Spinal Cord Transection

[Objectives] This study aimed to study the distribution characteristics of DRD3(dopamine receptor-3) and the changes in its expression before and after spinal cord injury(SCI), in order to lay a morphological basis for later research. [Methods] Adult male Wistar rats were randomly divided into sham operation group and SCI group. The rat spinal cord transection model at the sacral 2(S_2) segment was established. Rat tail spasticity score was performed 60 d after SCI, and the rats with 4-5 points were screened for perfusion. The expression of DRD3 in the sacral spinal cord(S+C segment) was detected by immunofluorescence. [Results] In normal rats, DRD3 was mainly distributed in the dorsal horn(DH), intermediate zone(IMZ) and ventral horn(VH) of the gray matter. It was also expressed in the white matter of the spinal cord. After SCI, the distribution of DRD3 in the segment below the injury section was similar to that of normal rats. However, the expression was different(P<0.05). [Conclusions] There was no significant change in the distribution of DRD3 in spinal cord after SCI. After the spinal cord S_2 was completed transected, the expression of DRD3 was significantly reduced in the DH, IMZ and VH regions of the gray matter of the spinal cord.

Research on Concrete Beam Crack Recognition Algorithm Based on Block Threshold Value Image Processing

To solve the problem that the digital image recognition accuracy of concrete structure cracks is not high under the condition of uneven ill umination and complex surface color of concrete structure,this paper has proposed a block segmentation method of maximum entropy threshold based on the digital image data obtained by the ACTIS automatic detection system.The steps in this research are as follows:1.The crack digital images of concrete specimens with typical fea-tures were collected by using the Actis system of KURABO Co,Ltd,of Japan in the concrete beam bending test.2.The images are segmented into blocks to dis-tinguish backgrounds of different grayscale.3.The max imum interclass average gray difference method is used to distinguish the sub-blocks and screen out the image blocks that need to be segmented.4.Segmentation is made to the image with 2D max imum entropy threshold segmentation method to obtain the binary image,and the target image can be obtained by screening the connected domain features of the binary image.Results have shown that compared with other algo-rithms,the proposed method can effectively decrease the image over-segmentation and under segmentation rates,highlight the characteristics of the target cracks,solve the problems of excessive difference between the identified length and actual length of cracks caused by background gray level change and uneven ilumnination,and effectively improve the recognition accuracy of bridge concrete cracks.

LaBr_(3)(Ce)-CsI(Tl)紧凑式叠层反康伽马探测器研制

本工作研制了一套由圆柱形LaBr_(3)(Ce)主晶体和井形CsI(Tl)次晶体组成的叠层伽马探测器,该探测器主要用于鉴别来自LaBr_(3)(Ce)主晶体的康普顿散射光子并进行反符合测量。两种不同的晶体耦合到同一个光电倍增管上。入射辐射沉积在每一层探测器的能量,可以通过PMT给出的信号脉冲形状差异进行识别。利用Geant4模拟结果,验证了脉冲形状甄别性能和康普顿散射抑制效果。利用^(60)Co伽马源对探测器进行了实验测试,测试结果表明,该探测器本底抑制系数为2.33(1),达到了康普顿本底抑制两倍以上的预期目标。

Neutron capture cross section of ^(169)Tm measured at the CSNS Back-n facility in the energy region from 30 to 300 keV

The capture cross sections of the ^(169)Tm(n,γ)reaction were measured at the back streaming white neutron beam line(Back-n)of the China Spallation Neutron Source(CSNS)using four C_(6)D_(6) liquid scintillation detectors.The background subtraction,normalization,and correction were carefully considered in the data analysis to obtain accurate cross sections.For the resonance at 3.9 eV,the R-matrix code SAMMY was used to determine the resonance parameters with the internal normalization method.The average capture cross sections of ^(169)Tm for energy between 30 and 300 keV were extracted relative to the ^(197)Au(n,γ)reaction.The measured cross sections of the ^(169)Tm(n,γ)reaction were reported in logarithmically equidistant energy bins with 20 bins per energy decade with a total uncertainty of 5.4%-7.0% in this study and described in terms of average resonance parameters using a Hauser-Feshbach calculation with fluctuations.The point-wise cross sections and the average resonance parameters showed fair agreement with the evaluated values of the ENDF/B-Ⅷ.0 library in the energy region studied.

Measurement of the differential cross sections and angle-integrated cross sections of the ~6Li(n,t)~4 He reaction from 1.0 eV to 3.0 MeV at the CSNS Back-n white neutron source

The^6 Li(n,t)~4 He reaction was measured as the first experiment involving neutron-induced charged particle emission reactions at the CSNS(China Spallation Neutron Source)Back-n white neutron source.The differential cross-sections of the^6 Li(n,t)~4 He reaction at 15 detection angles ranging from 19.2°to 160.8°are obtained from 1.0 eV to 3.0 MeV at 80 neutron energy points;for 50 energy points below 0.1 MeV they are reported for the first time.The results indicate that the anisotropy of the emitted tritium is noticeable above E_n=100 eV.The angle-integrated cross-sections are also obtained.The present differential cross-sections agree in general with the previous evaluations,but there are some differences in the details.More importantly,the present results indicate that the cross-sections of the^6 Li(n,t)~4 He reaction might be overestimated by most evaluations in the 0.5-3.0 MeV region,although they are recommended as standards below 1.0 MeV.

The C_(6)D_(6)detector system on the Back-n beam line of CSNS

Introduction The neutron capture cross sections are very important in the field of nuclear device design and basic physics research.Hydrogen-free liquid scintillator such as C_(6)D_(6)detectors are widely used in the neutron capture cross-sectional measurements for the low neutron sensitivity and fast time response.The Back-n white neutron source at China Spallation Neutron Source is the first spallation white neutron source in China,and it is suitable for neutron capture cross-sectional measurement.Materials and methods A C_(6)D_(6)detector system was built in the Back-n experimental station.The pulse height weighting technique was used to determine the system’s detection efficiency.The response to gamma rays of the C_(6)D_(6)detector was measured,and the energy resolution function was determined.Monte Carlo simulation with Geant4 code was carried out to get the weighting function of this C_(6)D_(6)detector system.Additionally,the systematic uncertainty of the weighting function was also determined.Conclusion According to the experimental and simulation results,this C_(6)D_(6)detector system can be used to measure neutron capture cross section.

Measurements of differential and angle-integrated cross sections for the 10B（n, α）7Li reaction in the neutron energy range from 1.0 eV to 2.5 MeV

Differential and angle-integrated cross sections for the 10B(n,α)^7 Li,10B(n,α0)^7 Li and 10B(n,α1)^7 Li^*reactions have been measured at CSNS Back-n white neutron source.Two enriched(90%)10B samples 5.0 cm in diameter and^85.0μg/cm^2 in thickness each with an aluminum backing were prepared,and back-to-back mounted at the sample holder.The charged particles were detected using the silicon-detector array of the Light-charged Particle Detector Array(LPDA)system.The neutron energy En was determined by TOF(time-of-flight)method,and the valid a events were extracted from the En-Amplitude two-dimensional spectrum.With 15 silicon detectors,the differential cross sections of a-particles were measured from 19.2°to 160.8°.Fitted with the Legendre polynomial series,the(n,a)cross sections were obtained through integration.The absolute cross sections were normalized using the standard cross sections of the 10B(n,α)^7 Li reaction in the 0.3-0.5 MeV neutron energy region.The measurement neutron energy range for the 10B(n,α)^7 Li reaction is 1.0 eV≤En<2.5 Me V(67 energy points),and that for the 10B(n,α0)^7 Li and10B(n,α1)^7 Li^*reactions is 1.0 eV≤En<1.0 MeV(59 energy points).The present results have been analyzed by the resonance reaction mechanism and the level structure of the 11B compound system,and compared with existing measurements and evaluations.

Initial years'neutron-induced cross-section measurements at the CSNS Back-n white neutron source

The Back-n white neutron source(known as Back-n)is based on back-streaming neutrons from the spallation target at the China Spallation Neutron Source(CSNS).With its excellent beam properties,e.g.,a neutron flux of approximately 1.8×107 n/cm2/s at 55 m from the spallation target,energy range spanning from 0.5 eV to 200 MeV,and time-of-flight resolution of a few per thousand,along with the equipped physical spectrometers,Back-n is considered to be among the best facilities in the world for carrying out nuclear data measurements.Since its completion and commencement of operation in May 2018,five types of cross-section measurements concerning neutron capture cross-sections,fission cross-sections,total cross-sections,light charged particle emissions,in-beam gamma spectra,and more than forty nuclides have been measured.This article presents an overview of the experimental setup and result analysis on the neutron-induced cross-section measurements and gamma spectroscopy at Back-n in the initial years.

Measurement of differential cross sections of neutron-induced deuteron production reactions on carbon from 25 to 52 MeV

The angle-differential cross sections of neutron-induced deuteron production from carbon were measured at six neutron energies from 25 to 52 MeV relative to those of n-p elastic scattering at the China Spallation Neutron Source(CSNS)Back-n white neutron source.By employing theΔE-E telescopes of the Light-charged Particle Detector Array(LPDA)system at 15.1°to 55.0°in the laboratory system,ratios of the angle-differential cross sections of the ^(12)C(n,xd)reactions to those of the n-p scattering were measured,and then,the angle-differential cross sections of the ^(12)C(n,xd)reactions were obtained using the angle-differential cross sections of the n-p elastic scattering from the JENDL-4.0/HE-2015 library as the standard.The obtained results are compared with data from previous measurements,all of which are based on mono-energic neutrons,the evaluated data from the JENDL-4.0/HE-2015 library and the ENDF-B/VIII.0 library,and those from theoretical calculations based on INCA code and Talys-1.9 code.Being the first white-neutron-source-based systematic measurement of the angle-differential cross sections of neutron-induced deuteron production reactions on carbon in several tens of MeV,the present work can provide a reference to the data library considering the lack of experimental data.