检索结果-南通市图书馆

Baicalin attenuates blood-spinal cord barrier disruption and apoptosis through PI3K/Akt signaling pathway after spinal cord injury

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2022年第5期17卷 1080-1087页

作者： Rui zhao Xue wu Xue-Yuan Bi Hao Yang Qian zhang College of Pharmacy Shaanxi University of Chinese MedicineXi’anShaanxi ProvinceChina Key Laboratory of the Ministry of Education for Medicinal Resources and Natural Pharmaceutical Chemistry National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest ChinaCollege of Life SciencesShaanxi Normal UniversityXi’anShaanxi ProvinceChina Translational Medicine Center Hong Hui HospitalXi’an Jiaotong UniversityXi’anShaanxi ProvinceChina Department of Pharmacy Hong Hui HospitalXi’an Jiaotong UniversityXi’anShaanxi ProvinceChina

Baicalin is a natural active ingredient isolated from Scutellariae Radix that can cross the blood-brain barrier and exhibits neuroprotective effects on multiple central nervous system diseases.However,the mechanism behind the neuroprotective effects remains unclear.In this study,rat models of spinal cord injury were established using a modified Allen's impact method and then treated with intraperitoneal injection of Baicalin.The results revealed that Baicalin greatly increased the Basso,Beattie,Bresnahan Locomotor Rating Scale score,reduced blood-spinal cord barrier permeability,decreased the expression of Bax,Caspase-3,and nuclear factorκB,increased the expression of Bcl-2,and reduced neuronal apoptosis and pathological spinal cord injury.SH-SY5 Y cell models of excitotoxicity were established by application of 10 m M glutamate for 12 hours and then treated with 40μM Baicalin for 48 hours to investigate the mechanism of action of Baicalin.The results showed that Baicalin reversed tight junction protein expression tendencies(occludin and ZO-1)and apoptosis-related protein expression(Bax,Bcl-2,Caspase-3,and nuclear factor-κB),and also led to up-regulation of PI3 K and Akt phosphorylation.These effects on Bax,Bcl-2,and Caspase-3 were blocked by pretreatment with the PI3 K inhibitor LY294002.These findings suggest that Baicalin can inhibit bloodspinal cord barrier permeability after spinal cord injury and reduce neuronal apoptosis,possibly by activating the PI3 K/Akt signaling pathway.This study was approved by Animal Ethics Committee of Xi'an Jiaotong University on March 6,2014.

关键词： apoptosis baicalin blood-spinal cord barrier natural products neuron PI3K/Akt signaling pathway spinal cord injury tight junction

Fire Detection Algorithm Based on an Improved Strategy of YOLOv5 and Flame Threshold Segmentation

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2023年第6期75卷 5639-5657页

作者： zhao Yuchen wu Shulei Wang Yaoru Chen Huandong zhang Xianyao zhao Hongwei School of Information Science and Technology Hainan Normal UniversityHaikou571158China

Due to the rapid growth and spread of fire,it poses a major threat to human life and property.Timely use of fire detection technology can reduce disaster losses.The traditional threshold segmentation method is unstable,and the flame recognition methods of deep learning require a large amount of labeled data for training.In order to solve these problems,this paper proposes a new method combining You Only Look Once version 5(YOLOv5)network model and improved flame segmentation algorithm.On the basis of the traditional color space threshold segmentation method,the original segmentation threshold is replaced by the proportion threshold,and the characteristic information of the flame is maximally retained.In the YOLOv5 network model,the training module is set by combining the ideas of Bootstrapping and cross validation,and the data distribution of YOLOv5 network training is adjusted.At the same time,the feature information after segmentation is added to the data set.Different from the training method that uses large-scale data sets for model training,the proposed method trains the model on the basis of a small data set,and achieves better model detection results,and the detection accuracy of the model in the validation set reaches 0.96.Experimental results show that the proposed method can detect flame features with faster speed and higher accuracy compared with the original method.

关键词： YOLOv5 fire safety deep learning flame detection

High-precision double-spike Cd isotopic measurements of seawater by MC-ICP-MS and its application to seawater affected by hydrothermal vent fluids

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

地球化学学报(英文) 2023年第5期42卷 934-942页

作者： Chuanwei Zhu Yunzhu wu Hanjie Wen Guanghai wu Wenrui Song Yuxu zhang Bo zhao State Key Laboratory of Ore Deposit Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China School of Earth Resources China University of GeosciencesWuhan 430074China School of Earth Sciences and Resources Chang’An UniversityXi’an 710054China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China Key Laboratory of Submarine Geosciences Second Institute of OceanographyMNRHangzhou 310012China Institute of Land Engineering and Technology Shaanxi Provincial Land Engineering Construction Group Co.Ltd.Xi’an 710075ShaanxiChina

Cadmium(Cd)isotopes in seawater have been proven as an important geochemical tool for tracing ocean Cd circulation in the modern ocean.In this study,we evaluated a new method to separate Cd(*60 ng)from seawater using Chelex resin(1.0 g)coupled with AG-MP-1M resin.The results show that the Chelex resin is suffi-cient to remove Cd from Na and Mg matrix with Cd recoveries at 98.3±3.5%(2SD,N=6);while AG-MP-1M resin could separate Cd from the residual Na,Mg,and isobaric inferences.The total Cd recoveries of the method are 96.3±1.5%(2SD;N=4)and the salinity of the samples has no significant impacts on Cd recovery.Cd isotope ratios were measured using a Nu PlasmaⅢMC-ICP-MS and^(111)Cd–^(110)Cd double spike technique.By comparing theδ^(114/110)Cd values(0.00±0.06%)of synthetic seawaters doped with Cd isotope standard(NIST-3108;treated by Chelex+AG-MP-1M resin)and the reference value(-0.00%),no variations were observed.We also analyzed the Cd isotope compositions of three deep seawaters from a column at the Southwest Indian Ocean Ridges(SWIR).Theδ^(114/110)Cd values of the col-umn are decreased from 1.05±0.05%at 3200 m to 0.36±0.05%at 2800 m,differing from reportedδ^(114/110)Cd values of deep seawater in other oceans.Considering the spatial distance between the column and active hydrothermal vents in SWIR(-13 km),we propose that such positiveδ^(114/110)Cd values of deep seawater were likely contaminated by vent fluids,which could provide heavy Cd isotope to deep seawaters.This study demon-strates that Cd isotope is more sufficient to distinguish the impact of plumes on deep seawater.

关键词： Cd isotope Seawater Plume Hydrothermal system

An Image Denoising Model via the Reconciliation of the Sparsity and Low-Rankness of the Dictionary Domain Coefficients

在线全文

学校读者我要写书评

暂无评论

wuhan University Journal of Natural Sciences 2023年第1期28卷 61-67页

作者： YANG Yifan zhang Tao wu Di zhao Yu Key Laboratory of Multidisciplinary Management and Control of Complex Systems of Anhui Higher Education Institutes Anhui University of TechnologyMaanshan 243002AnhuiChina School of Mathematics and Physics Anhui University of TechnologyMaanshan 243032AnhuiChina

Sparse coding has achieved great success in various image restoration tasks.However,if the sparse representation coefficients of the structure(low-frequency information)and texture(high-frequency information)components of the image are under the same penalty constraint,the restoration effect may not be ideal.In this paper,an image denoising model combining mixed norm and weighted nuclear norm as regularization terms is proposed.The proposed model simultaneously exploits the group sparsity of the high frequency and lowrankness of the low frequency in dictionary-domain.The mixed norm is used to constrain the high frequency part and the weighted nuclear norm is used to constrain the low frequency part.In order to make the proposed model easy to solve under the framework of alternative direction multiplier method(ADMM),iterative shrinkage threshold method and weighted nuclear norm minimization method are used to solve the two sub-problems.The validity of the model is verified experimentally through comparison with some state-of-the-art methods.

关键词： image denoising mixed norm sparse representation principal component analysis(PCA)dictionary

The effect of ergosterol on the allogrooming behavior of termites in response to the entomopathogenic fungus Metarhiziumanisopliae

在线全文

学校读者我要写书评

暂无评论

Insect Science 2023年第1期30卷 185-196页

作者： Yong Chen Chongwen zhao Wenhui Zeng Wenjing wu Shijun zhang Dandan zhang Zhiqiang Li Guangdong Key Laboratory of Animal Conservation and Resource Utilization Guangdong Public Laboratory of Wild Animal Conservation and UtilizationInstitute of ZoologyGuangdong Academy of SciencesGuangzhouChina School of Ecology Sun Yat-sen UniversityGuangzhouChina

Termites have physiological and behavioral immunities that make them highly resistant to pathogen infections,which complicates biocontrol efforts.However,the stimuli that trigger the pathogen-avoidance behaviors of termites are still unclear.Our study shows that workers of Coptotermes formosanus exposed to the conidia of Metarhizium anisopliae exhibited a significantly higher frequency and longer duration of allogrooming behaviors compared with untreated termites.Volatile compounds in the cuticle of control termites and termites previously exposed to a suspension of M.anisopliae conidia were analyzed and compared using a gas chromatography-mass spectrometer(GC-MS).Our results showed that the amount of ergosterol differed between the fungus-exposed and control termites.Choice tests showed that termites significantly preferred to stay on filter paper treated with ergosterol(0.05,0.1,or 1.0 mg/mL)compared with control filter paper.In addition,termites exposed to ergosterol followed by M.anisopliae conidia were allogroomed at a significantly higher frequency and for a longer duration than termites exposed to alcohol(the solvent used with the ergosterol in the ergosterol trials)alone followed by M.anisopliae conidia.These results showed that ergosterol may enhance the allogrooming behavior of termites in the presence of entomopathogenic fungi.

关键词： allogrooming behavior entomopathogenic fungus ergosterol recognition social immunity termite

Controlled Ring-opening(Co)Polymerization of Renewable Macrolactones by Al-based Catalysts with Different Sidearms

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2023年第11期41卷 1706-1713,I0006页

作者： wu-Chao zhao Jing Yuan Jiang-Hua He Yue-Tao zhang State Key Laboratory of Supramolecular Structure and Materials College of ChemistryJilin UniversityChangchun 130012China

It remains a challenging task to achieve ring-opening(co)polymerization(ROP)of macrolactones.Hence,we synthesized a series of Al-based catalysts and systemically investigated the effect of N-containing substituent on the sidearms on ROP of macrolactones.Al3 possessing Nmethyl group could effectively achieve controlled ROP of pentadecalactone(PDL)and macro(di)lactone ethylene brassylate(EB)in combination with BnOH,furnishing polyethylene-like PPDL and PEB with M_(W)up to 90.3 and 321 kg/mol,respectively.Random copolymerization of PDL and small-ring lactonesε-caprolactone(e-CL)andδ-valerolactone(δ-VL)could prepare random copolyesters with tailored T_(m)in the range of 57-94℃by controlling the ratios of PDL and e-CL,6-VL.More importantly,well-defined block copolyesters could be obtained by sequential adding PDL andε-CL,δ-VL,which have been proved by GPC-MALLS,DSC and^(13)C-NMR.

关键词： Ring-opening(co)polymerization Macrolactones Polyethylene-like polymers Sidearm effect Aluminum complex

Investigation of heavy ion irradiation effects on 650-V p-GaN normally-off HEMTs

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2022年第8期65卷 254-260页

作者： Yinhe wu Jincheng zhang Shenglei zhao zhaoxi wu Zhongxu WANG Bo MEI Chao DUAN Dujun zhao Weihang zhang Zhihong LIU Yue HAO Key Laboratory of Wide Band-Gap Semiconductors and Devices School of MicroelectronicsXidian University China Aerospace Components Engineering Center

In this study, we investigate heavy ion irradiation effects on commercial 650 V p-GaN normallyoff HEMTs. Ge and Cl ions are used to irradiate the GaN devices in the experiments. Ge and Cl ion beam irradiation have little impact on the output characteristics of GaN devices. After heavy ion irradiation, the leakage currents between source and drain electrodes increase significantly under off-state, decreasing the breakdown voltage(BVDS) sharply. Additionally, Ge and Cl ion irradiation have little effect on the trap states under the gate electrode; thus, the gate leakage currents increase slightly. Many line-shaped crystal defects extending from the surface to the GaN buffer layer can be captured using a transmission electron microscope after Ge/Cl ion irradiation. The buffer layers of the irradiated devices were damaged, and the leakage path was generated in the buffer layer. Defect percolation process in buffer layer is the dominant factor of irradiated high-voltage GaN device failure.

关键词： heavy ions irradiation p-GaN normally-off HEMTs line-shaped crystal defects leakage path defect percolation process

Abnormal Systemic and Ocular Responses to the Valsalva Manoeuvre in Primary Open-Angle Glaucoma:A Case for Autonomic Failure?

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Current Medical Science 2023年第2期43卷 376-383页

作者： Bin-bin LIU Bo-wen zhao Fei-peng wu Tian HU Yin zhao Hong zhang Department of Ophthalmology Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan430030China

Objective This study aimed to examine the association of primary open-angle glaucoma(POAG)with autonomic dysfunction by assessing the differences in systemic and ocular responses to an autonomic provocation test,the Valsalva manoeuvre(VM),between POAG patients and normal subjects.Methods Forty POAG and forty control subjects were subjected to the VM.Systemic and ocular parameters were measured at baseline,phase 2,and phase 4 of the VM(VM2 and VM4),where VM2 and VM4 are sympathetic and parasympathetic nervous activation states,respectively.Heart rate variability was used to assess the autonomic nervous activity,among which the high-frequency component(HF)and the low-frequency(LF)/HF ratio were used as indices of parasympathetic and sympathetic activation,respectively.Results POAG patients demonstrated higher sympathetic activation(LF/HF ratio median:2.17 vs.1.53,P=0.000)than controls at baseline and exhibited attenuated sympathetic and parasympathetic responses(a smaller change in LF/HF and HF values)during the VM than controls.During VM,the intraocular pressure(IOP),mean blood pressure(MAP),mean ocular perfusion pressure(MOPP),and the Schlemm’s canal area(SCAR)increased from baseline to VM2 and then decreased from VM2 to VM4 in both the POAG and control groups(all P<0.05).However,when we compared the changes above,the fluctuations in IOP,MAP,and MOPP were more pronounced in POAG than in controls(all P<0.05),while the changes in amplitudes of SCAR were smaller in POAG(P<0.05).Furthermore,from VM2 to VM4,the choroid thickness(ChT)in the POAG group was significantly decreased,while it was unchanged in normal subjects(P=0.258).A regression analysis showed a significant correlation of the baseline LF/HF with IOP change values(ΔIOP)from baseline to VM2 in POAG(R^(2)=0.147,P=0.014).Conclusion Patients with POAG showed more pronounced fluctuations in IOP,MAP,MOPP and ChT during the VM than controls.These reactions could be associated with autonomic dysfunction in POAG.

关键词： primary open-angle glaucoma Valsalva manoeuvre autonomic dysfunction intraocular pressure Schlemm’s canal

Analysis of the Light Concentration Loss of a Fresnel CPV/T System after Dust Accumulation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Thermal Science 2022年第6期31卷 1868-1880页

作者： zhao Ning YAN Suying MA Xiaodong wu Ze MING Tingzhen zhao Xiaoyan zhang Na College of Energy and Power Engineering Inner Mongolia University of TechnologyHohhot O10051China School of Civil Engineering and Architecture Wuhan University of TechnologyWuhan 430070China Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China

Dust accumulation is one of the reasons for the performance degradation of concentrating photovoltaic and thermal(CPV/T) systems due to the deposition of dust particles with different compositions, shapes, sizes, and masses. In this work, an optical model was developed to investigate the influence of the particle size, diameter, shape, and deposition density on the light concentration efficiency, using the Monte Carlo raytracing(MCRT) method in the Tracepro software. The triangular particles had a larger influence on the light ray deflection and energy flux degradation than the circular and square particles. An average increase in the dust density of 1 g/m^(2) decreased the light concentration efficiency of particles with sizes smaller than 50 μm and 60 μm by 3.31% and 3.26%, respectively. Furthermore, the effect of the incidence angle on the light concentration efficiency was considered at an angle less than 2°.

关键词： dust accumulation Fresnel CPV/T system light concentration efficiency Monte Carlo raytracing