A review of rock macro-indentation:Theories,experiments,simulations,and applications

Rock macro-indentation plays a fundamental role in mechanical rock breaking for various rock engineering application,such as drilling,tunneling,cutting,and sawing.Over the past decades,extensive research has been conducted to understand the indentation mechanisms and responses through various approaches.This review aims to provide an overview of the current status and recent advancements in theories,experiments,numerical simulations,and applications of macro-indentation in rock engineering.It starts with elaborating on the mechanisms of macro-indentation,followed by a discussion of the merits and limitations of commonly used models.Influence factors and their effects on indentation test results are then summarized.Various numerical simulation methods for rock macro-indentation are highlighted,along with their advantages and disadvantages.Subsequently,the applications of indentation tests and indentation indices in characterizing rock properties are explored.It reveals that compression-tension,compression-shear,and composite models are widely employed in rock macroindentation.While the compression-tension model is straightforward to use,it may overlook the anisotropic properties of rocks.On the other hand,the composite model provides a more comprehensive description of rock indentation but requires complex calculations.Additionally,factors,such as indentation rate,indenter geometry,rock type,specimen size,and confining pressure,can significantly influence the indentation results.Simulation methods for macro-indentation encompass continuous medium,discontinuous medium,and continuous-discontinuous medium methods,with selection based on their differences in principle.Furthermore,rock macro-indentation can be practically applied to mining engineering,tunneling engineering,and petroleum drilling engineering.Indentation indices serve as valuable tools for characterizing rock strength,brittleness,and drillability.This review sheds light on the development of rock macro-indentation and its extensive application in engineering practice.Specialists in the field can gain a comprehensive understanding of the indentation process and its potential in various rock engineering endeavors.

Experimental study on the influences of cutter geometry and material on scraper wear during shield TBM tunnelling in abrasive sandy ground

When shield TBM tunnelling in abrasive sandy ground,the rational design of cutter parameters is critical to reduce tool wear and improve tunnelling efficiency.However,the influence mechanism of cutter parameters on scraper wear remains unclear due to the lack of a reliable test method.Geometry and material optimisation are often based on subjective experience,which is unfavourable for improving scraper geological adaptability.In the present study,the newly developed WHU-SAT soil abrasion test was used to evaluate the variation in scraper wear with cutter geometry,material and hardness.The influence mechanism of cutter parameters on scraper wear has been revealed according to the scratch characteristics of the scraper surface.Cutter geometry and material parameters have been optimised to reduce scraper wear.The results indicate that the variation in scraper wear with cutter geometry is related to the cutting resistance,frictional resistance and stress distribution.An appropriate increase in the front angle(or back angle)reduces the cutting resistance(or frictional resistance),while an excessive increase in the front angle(or back angle)reduces the edge angle and causes stress concentration.The optimal front angle,back angle and edge angle for quartz sand samples areα=25°,β=10°andγ=55°,respectively.The wear resistance of the modelled scrapers made of different metal materials is related to the chemical elements and microstructure.The wear resistances of the modelled scrapers made of 45#,06Cr19Ni10,42CrMo4 and 40CrNiMoA are 0.569,0.661,0.691 and 0.728 times those made of WC-Co,respectively.When the alloy hardness is less than 47 HRC(or greater than 58 HRC),scraper wear decreases slowly with increasing alloy hardness as the scratch depth of the particle asperity on the metal surface stabilizes at a high(or low)level.However,when the alloy hardness is between 47 HRC and 58 HRC,scraper wear decreases rapidly with increasing alloy hardness as the scratch depth transitions from high to low levels.The sensitive hardness interval and recommended hardness interval for quartz sand are[47,58]and[58,62],respectively.The present study provides a reference for optimising scraper parameters and improving cutterhead adaptability in abrasive sandy ground tunnelling.

4-丁基间苯二酚微乳凝胶制备及美白抗氧化研究

通过配方筛选优化制备含有4-丁基间苯二酚的肉桂油微乳凝胶,考察其制剂学性质,并对其进行美白及抗氧化性能的评价。含有4-丁基间苯二酚的肉桂油微乳外观澄清透明,粒径15.68 nm、多分散系数(PDI)0.185。以卡波姆和白芨多糖作为凝胶基质制备微乳凝胶,该微乳凝胶的pH值为6.0,黏度为74.8 Pa·s,符合外用凝胶剂质量要求。通过酪氨酸酶抑制率实验测定4-丁基间苯二酚肉桂油微乳凝胶的美白功效,该微乳凝胶的酪氨酸酶抑制率随着质量浓度增加而逐渐增强,且微乳凝胶的酪氨酸酶抑制率均高于同等质量浓度下的游离4-丁基间苯二酚和熊果苷,表明4-丁基间苯二酚肉桂油微乳凝胶具有良好的美白功效。通过4-丁基间苯二酚肉桂油微乳凝胶对过氧化氢(H_(2)O_(2))诱导B16-F10细胞氧化损伤保护作用的测定,评价其抗氧化性能,结果表明4-丁基间苯二酚肉桂油微乳凝胶在0.1μg/mL质量浓度下无细胞毒性,通过抑制ROS产生抑制H_(2)O_(2)引起的B16-F10细胞损伤。

Design of the solar X-ray detector for the Macao Science Satellite-1B

The solar X-ray detector(SXD)onboard the Macao Science Satellite-1B was designed to monitor solar flare bursts and to study the solar activity in the 25th solar cycle.The SXD includes two parts:a soft X-ray detection unit and a hard X-ray detection unit.Both the soft X-ray detection unit and the hard X-ray detection unit include two collimators,two X-ray detectors(a silicon drift detector and a cadmium-zinc-telluride detector),and a processing circuit.Compared with similar instruments,the energy range of the SXD is wider(1–600 ke V)and the energy resolution is better(150 e V at 5.9 ke V,12%at 59.5 ke V,and 3%at 662 keV).

Real-world effectiveness and safety of goserelin 10.8-mg depot in Chinese patients with localized or locally advanced prostate cancer

Objective:Real-word data on long-acting luteinizing hormone-releasing hormone(LHRH)agonists in Chinese patients with prostate cancer are limited.This study aimed to determine the real-world effectiveness and safety of the LHRH agonist,goserelin,particularly the long-acting 10.8-mg depot formulation,and the follow-up patterns among Chinese prostate cancer patients.Methods:This was a multicenter,prospective,observational study in hormone treatment-na?ve patients with localized or locally advanced prostate cancer who were prescribed goserelin 10.8-mg depot every 12 weeks or 3.6-mg depot every 4 weeks with or without an anti-androgen.The patients had follow-up evaluations for 26 weeks.The primary outcome was the effectiveness of goserelin in reducing serum testosterone and prostate-specific antigen(PSA)levels.The secondary outcomes included testosterone and PSA levels,attainment of chemical castration(serum testosterone<50 ng/d L),and goserelin safety.The exploratory outcome was the monitoring pattern for serum testosterone and PSA.All analyses were descriptive.Results:Between September 2017 and December 2019,a total of 294 eligible patients received≥1 dose of goserelin;287 patients(97.6%)were treated with goserelin 10.8-mg depot.At week 24±2,the changes from baseline[standard deviation(95%confidence interval)]in serum testosterone(n=99)and PSA(n=131)were-401.0 ng/d L[308.4 ng/d L(-462.5,-339.5 ng/d L)]and-35.4 ng/m L[104.4 ng/m L(-53.5,-17.4 ng/m L)],respectively.Of 112 evaluable patients,100(90.2%)achieved a serum testosterone level<50 ng/d L.Treatment-emergent adverse events(TEAEs)and severe TEAEs occurred in 37.1%and 10.2%of patients,respectively.The mean testing frequency(standard deviation)was 1.6(1.5)for testosterone and 2.2(1.6)for PSA.Conclusions:Goserelin 10.8-mg depot effectively achieved and maintained castration and was well-tolerated in Chinese patients with localized and locally advanced prostate cancer.

A multi-modal clustering method for traditonal Chinese medicine clinical data via media convergence

Media convergence is a media change led by technological innovation.Applying media convergence technology to the study of clustering in Chinese medicine can significantly exploit the advantages of media fusion.Obtaining consistent and complementary information among multiple modalities through media convergence can provide technical support for clustering.This article presents an approach based on Media Convergence and Graph convolution Encoder Clustering(MCGEC)for traditonal Chinese medicine(TCM)clinical data.It feeds modal information and graph structure from media information into a multi-modal graph convolution encoder to obtain the media feature representation learnt from multiple modalities.MCGEC captures latent information from various modalities by fusion and optimises the feature representations and network architecture with learnt clustering labels.The experiment is conducted on real-world multimodal TCM clinical data,including information like images and text.MCGEC has improved clustering results compared to the generic single-modal clustering methods and the current more advanced multi-modal clustering methods.MCGEC applied to TCM clinical datasets can achieve better results.Integrating multimedia features into clustering algorithms offers significant benefits compared to single-modal clustering approaches that simply concatenate features from different modalities.It provides practical technical support for multi-modal clustering in the TCM field incorporating multimedia features.

Hybrid Optimization Algorithm in the Photometric Inversion of Periods for Asteroids

Asteroids,as the primitive building blocks for the formation of our solar system,could reveal its evolution mechanism,and have attracted more and more attention from the public and professional institutions in recent years.Their physical properties,such as rotational period,spin axis and overall shape,can be inverted from ground-and space-based photometric observations.Since the inversion process is very time-consuming,this paper combines the genetic algorithm with the Levenberg–Marquardt(LM) algorithm,and presents a hybrid optimization algorithm based on a Cellinoid shape model for the inversion of rotational periods,which greatly improves the inversion efficiency.The proposed hybrid algorithm is applied to the synthetic lightcurves generated for an assumed Cellinoid shape model and the inverted rotational period results are consistent with the preset ones with a reduced search time,compared with the LM algorithm.Finally,multiple numerical experiments on the periods are performed on lightcurves and sparse observations of real asteroids to confirm that the proposed method can perform well in improving computational efficiency.

石墨烯材料制备技术研究进展

石墨烯是二维晶体结构的碳纳米材料,其具有优异的导电、导热、光学和力学特性引起了研究者的浓厚兴趣,在材料、电子、物理、化学、能源、生物医药等众多领域具有广阔的应用前景。本文详细综述了近年来国内外参考文献对于石墨烯制备方法的研究,并指出了目前各种石墨烯制备方法中存在的问题。最后,本文对石墨烯制备方法的改进方向进行了展望。

Responses of vegetation cover to the Grain for Green Program and their driving forces in the He-Long region of the middle reaches of the Yellow River

The implementation of the Grain for Green Program is a great breakthrough in the history of China＇s ecological environment construction,which can control soil erosion effectively,increase land productivity and improve the ecological environment.To investigate the eco-environmental benefits brought by the Grain for Green Program,the spatiotemporal variations of vegetation cover in the growing season from 2000 to 2010 across the Hekou-Longmen （He-Long） region were analyzed by using remote sensing information,meteorological data and land use data.Moreover,the impacts of climate and human activities on vegetation change were evaluated objectively.Annual vegetation cover in the growing season increased very significantly.Increased vegetation cover occurred in 98.7％ of the region,of which the area for vegetation cover improved slightly constituted 79.8％ of the whole area.Vegetation moderately improved was mainly distributed in the south of the He-Long region,covering 9.6％ of the area,and the area for vegetation basically unchanged concentrated in the middle and upper reaches of the Wuding River.Precipitation was found to be an important natural factor influencing vegetation cover change.The area of vegetation cover showing a significantly positive correlation with precipitation occupied 22.14％ of the region.As driven by policies from the Grain for Green Program,forestland increased significantly and land use structure became more intensive.Human activities played a positive and effective role in the protection,restoration and improvement of vegetation in the places where vegetation cover was basically unchanged,even though precipitation declined greatly,and vegetation improved moderately with massive increases of forestland and grassland.

HrcQ is necessary for Xanthomonas oryzae pv. oryzae HR-induction in non-host tobacco and pathogenicity in host rice

Bacterial blight, caused by Xanthomonas oryzae pv. oryzae(Xoo), is one of the most destructive diseases of rice(Oryza sativa L.) worldwide. The type III secretion system(T3SS) of Xoo, encoded by the hrp(hypersensitive response and pathogenicity) genes, plays critical roles in conferring pathogenicity in host rice and triggering a hypersensitive response(HR) in non-host plants. To investigate the major genes conferring the pathogenicity and avirulence of Xoo, we previously constructed a random Tn5-insertion mutant library of Xoo strain PXO99A. We report here the isolation and characterization of a Tn5-insertion mutant PXM69. Tn5-insertion mutants were screened on indica rice JG30, which is highly susceptible to PXO99A, by leaf-cutting inoculation.Four mutants with reduced virulence were obtained after two rounds of screening. Among them, the mutant PXM69 had completely lost virulence to the rice host and ability to elicit HR in non-host tobacco. Southern blotting analysis showed a single copy of a Tn5-insertion in the genome of PXM69. PCR walking and sequencing analysis revealed that the Tn5 transposon was inserted at nucleotide position 70,192–70,201 in the genome of PXO99A, disrupting the type III hrc(hrp-conserved) gene hrcQ, the first gene in the D operon of the hrp cluster in Xoo. To confirm the relationship between the Tn5-insertion and the avirulence phenotype of PXM69, we used the marker exchange mutagenesis to create a PXO99Amutant, ΔhrcQ::KAN, in which the hrcQ was disrupted by a kanamycin-encoding gene cassette at the same site as that of the Tn5-insertion. ΔhrcQ::KAN showed the same phenotype as mutant PXM69. Reintroduction of the wild-type hrcQ gene partially complemented the pathogenic function of PXM69. RT-PCR and cellulase secretion assays showed that the Tn5-disruption of hrcQ did not affect transcription of downstream genes in the D operon and function of the type II secretion system. Our results provide new insights into the pathogenic functions of clustered hrp genes in Xoo.

Review of lithium-ion battery state of charge estimation

The technology deployed for lithium-ion battery state of charge(SOC)estimation is an important part of the design of electric vehicle battery management systems.Accurate SOC estimation can forestall excessive charging and discharging of lithium-ion batteries,thereby improving discharge efficiency and extending cycle life.In this study,the key lithium-ion battery SOC estimation technologies are summarized.First,the research status of lithium-ion battery modeling is introduced.Second,the main technologies and difficulties in model parameter identification for lithium-ion batteries are discussed.Third,the development status and advantages and disadvantages of SOC estimation methods are summarized.Finally,the current research problems and prospects for development trends are summarized.

外电场作用下离子液体振动光谱变化的分子动力学模拟研究

振动光谱学是研究液体分子微观结构的强有力工具,利用振动光谱学探究外界条件作用下液体结构性质的变化是可行的。本文利用分子动力学模拟方法研究了从0到10 V·nm^(−1)变化的外加电场对1-乙基-3-甲基咪唑六氟磷酸盐离子液体的振动光谱的影响,并且详细分析了位于50,183,3196,3396 cm^(−1)的振动峰的强度及位置随外加电场变化而变化的内在原因。随着外加电场从0增大到10 V·nm^(−1),由于模拟体系中平均每对阴阳离子的总偶极矩增大(从4.34到5.46 Debye)和阳离子的取向更加一致,使得位于50、183 cm^(−1)的振动峰的强度相应地逐渐增强。位于3196 cm^(−1)的振动峰的强度明显减弱,因为外加电场的作用使甲基和乙基侧链上碳原子周围的氢原子不断增多,从而使烷基链上碳氢键的伸缩振动受限。外加电场作用下分子间+C―H···F−氢键的减少使位于3396 cm^(−1)的振动峰的强度逐渐减弱。而位于50和3396 cm^(−1)的振动峰的红移现象分别归因于每对离子平均相互作用能的减小(从−378.7到−298.0 kJ·mol^(−1))和有利于氢键结合的弛豫效应。

Effects of ephedrine on expression of Nogo-A and synaptophysin in neonatal rats following hypoxic-ischemic brain damage

BACKGROUND： Central nervous system axons regenerate poorly following neonatal hypoxic-ischemic brain damage （HIBD）, partly due to inhibitors, such as Nogo-A. Very few studies have addressed the regulation of Nogo-A in neonatal rats following HIBD. However, numerous studies have shown that ephedrine accelerates neuronal remodeling and promotes recovery of neural function in neonatal rats following HIBD. OBJECTIVE： To investigate the effects of ephedrine on expression of Nogo-A and synaptophysin in brain tissues of neonatal rats following HIBD. DESIGN, TIME AND SETTING： A completely randomized, controlled study was performed at the Immunohistochemistry Laboratory of the Research Institute of Pediatrics, Children＇s Hospital of Chongqing Medical University from August 2008 to March 2009. MATERIALS： Ephedrine hydrochloride （Chifeng Pharmaceutical Group, China）, rabbit anti-Nogo-A polyclonal antibody （Abcam, UK）, and rabbit anti-synaptophysin polyclonal antibody （Lab Vision, USA） were used in this study. METHODS： A total of 96 healthy, neonatal, Sprague Dawley rats were randomly assigned to three groups （n = 32）： sham operation, HIBD, and ephedrine. The HIBD model was established by permanent occlusion of the left common carotid artery, followed by 2 hours of hypoxia （8% oxygen and 92% nitrogen）. In the sham operation group, the left common carotid artery was exposed, but was not ligated or subjected to hypoxia. Rats in the ephedrine group were intraperitoneally injected with ephedrine immediately following HIBD, with 1.5 mg/kg each time. Rats in the sham operation and HIBD groups were injected with an equal volume of saline. All neonatal rats were treated once daily for 7 days. MAIN OUTCOME MEASURES： Histopathological damage to the cortex and hippocampus was determined by hematoxylin-eosin staining. Expression of Nogo-A and synaptophysin was detected using immunohistochemical staining. RESULTS： Neuronal degeneration and edema were observed in the hypoxJc-Jschemic cortex and hippocampus by hematoxylin-eosin staining. Compared with the sham operation group, the levels of Nogo-A significantly increased in the HIBD group at various time points （P 〈 0.01）. Nogo-A expression was significantly reduced in the ephedrine group compared with the HIBD group （P 〈 0.01）. Synaptophysin expression was significantly decreased in the hypoxic-ischemJc cortex, compared with the sham operation group （P 〈 0.01）. Synaptophysin levels were significantly increased in the ephedrine group, compared with the HIBD group （P 〈 0.01）. CONCLUSION： Altered Nogo-A expression was associated with inversely altered synaptophysin expression. The use of ephedrine normalized expression levels of Nogo-A and synaptophysin following HIBD.

Biochar-based organic fertilizer application rates for Tetrastigma hemsleyanum planted under Moso bamboo

The under-forest economy has received increased attention in China.However,little is known about the effects of co-composted biochar on soil and plant biomass in under-forest planting systems.In this study,plant biomass,soil nutrient levels,and bacterial communities were evaluated after application of biochar-based organic fertilizer(BOF,derived from co-composted biochar-compost)at varying rates to soils supporting Tetrastigma hemsleyanum Diels&Gilg planted under a Moso bamboo(Phyllostachys edulis)forest.BOF treatment increased the biomass of T.hemsleyanum.Compared with the control,BOF application significantly increased soil pH and organic carbon(SOC).The high-throughput sequencing results showed significant differences in the Bacteroidetes,Verrucomicrobia,Chlorofexi,and OD1 phyla among all groups.At the genus level,the control group was characterized by a preponderance of Conexibacter.Rhodanobacter was enriched in soils with a 3%BOF application and Steroidobacter and Spirochaeta were the most prominent phyla in the 5%BOF group.There was no biomarker selected in the 1%BOF group at the genus level.In conclusion,BOF application increased the biomass of T.hemsleyanum when intercropped under a Moso bamboo forest;this effect may be due to changes in the soil physicochemical properties and microbial communities after BOF application.

3D-printed,bi-layer,biomimetic artificial periosteum for boosting bone regeneration

Periosteum,a membrane covering the surface of the bone,plays an essential role in maintaining the function of bone tissue—and especially in providing nourishment and vascularization during the bone regeneration process.Currently,most artificial periostea have relatively weak mechanical strength and a rapid degradation rate,and they lack integrated angiogenesis and osteogenesis functions.In this study,a bi-layer,biomimetic,artificial periosteum composed of a methacrylated gelatin–nano-hydroxyapatite(GelMA-nHA)cambium layer and a poly(N-acryloyl 2-lycine)(PACG)-GelMA-Mg^(2+)fibrous layer was fabricated via 3D printing.The GelMA-nHA layer is shown to undertake the function of improving osteogenic differentiation of rat bone marrow mesenchymal stem cells with the sustainable release of Ca^(2+) from nHA nanoparticles.The hydrogen-bonding-strengthened P(ACG-GelMA-L)-Mg^(2+)hydrogel layer serves to protect the inner defect site and prolong degradation time(60 days)to match new bone regeneration.Furthermore,the released magnesium ion exhibits a prominent effect in regulating the polarization phenotype of macrophage cells into theM2 phenotype and thus promotes the angiogenesis of the human umbilical vein endothelial cells in vitro.This bi-layer artificial periosteum was implanted into a critical-sized cranial bone defect in rats,and the 12-week post-operative outcomes demonstrate optimal new bone regeneration.

高效液相色谱法测定牙膏中防腐剂含量

为管理限制牙膏中防腐剂的种类与用量,提升牙膏质量,研究利用高效液相色谱法测定牙膏中防腐剂的含量。用对羟基苯甲酸甲酯、对羟基苯甲酸乙酯以及苯甲酸等5种试剂制备防腐剂混合标准溶液,利用乙腈等溶液处理牙膏样本,采用高效液相色谱仪,以磷酸二氢钠溶液、甲醇与乙腈混合溶液为流动相,在柱温为室温,进样量为5μL,流速为1.5 mL/min的条件下测定混合标准溶液与牙膏样本,并根据混合标准溶液色谱峰的保留时间与面积绘制标准曲线。结果显示:流动相内磷酸二氢钠溶液、甲醇与乙腈体积比为55∶25∶20的条件下,混合标准溶液的分离度最高;各类防腐剂回收率范围为88.68%~99.61%之间,相对标准偏差范围为0.39%~2.44%之间;重复性测试结果满足实际应用需求。

Optimal compatible doses and effects of ephedrine and naloxone on neural plasticity in cerebral ischemia/reperfusion rats

BACKGROUND： Ephedrine promotes neural plasticity in rats following cerebral ischemia/reperfusion injury. Ephedrine has been combined with naloxone in some studies, and it has been confirmed that their combination has synergistic effects on increasing neural plasticity following cerebral ischemia/reperfusion injury. OBJECTIVE： To investigate the effects of ephedrine combined with various doses of naloxone on neural plasticity and to find an optimal dose of naloxone in rats after cerebral ischemia/reperfusion injury by analyzing growth associated protein-43 （GAP-43）, synaptophysin and β-endorphin expression in the hippocampal CA3 area. DESIGN, TIME AND SETTING： This immunohistochemical, randomized, controlled, animal experiment was performed at the Chongqing Research Institute of Pediatrics, China from September 2007 to June 2008. MATERIALS： Ephedrine hydrochloride injection and naloxone hydrochloride injection were respectively purchased from Shandong Lvliang Pharmaceutical Factory, China and Sichuan Jingwei Pharmaceutical Co., Ltd., China. A total of 192 healthy adult Sprague Dawley rats were used to establish models of left middle cerebral artery occlusion using the suture occlusion method. METHODS： At 2 hours following cerebral ischemia, the rats were intraperitoneally injected with 1.5 mg/kg/d ephedrine （ephedrine group）, with 0.1, 0.2, or 0.3 mg/kg/d naloxone （low, moderate and high doses of naloxone groups）, with 1.5 mg/kg/d ephedrine ＋ 0.1, 0.2, or 0.3 mg/kg/d naloxone （ephedrine ＋ low, moderate and high doses of naloxone groups）, and with 0.5 mL saline （model group）, respectively. MAIN OUTCOME MEASURES： GAP-43, synaptophysin and β -endorphin expression were detected in the hippocampal CA3 area using immunohistochemistry 1-4 weeks after surgery. Sensorimotor integration in rats was assessed using the beam walking test. RESULTS： GAP-43 and synaptophysin expression was greater in the ephedrine group, and in the ephedrine ＋ moderate and high doses of naloxone groups compared with the model group. GAP-43 and synaptophysin expression was greatest in the ephedrine ＋ high dose of naloxone group at 2 and 3 weeks alter surgery. β -endorphin expression was significantly lower in the ephedrine group, and in the ephedrine ＋ moderate and high doses of naloxone groups compared with the model group （P 〈 0.05）. β -endorphin expression was persistently low in the ephedrine ＋ high dose of naloxone group. At 1-3 weeks after surgery, the beam walking test score was significantly higher in the ephedrine group and ephedrine ＋ various doses of naloxone groups than in the model group （P 〈 0.05）. The score was higher in the ephedrine ＋ moderate and high doses of naloxone groups than in the ephedrine group （P 〈 0.05）. Moreover, the score was increased as the dose of naloxone increased in the ephedrine ＋ various doses of naloxone groups. CONCLUSION： Ephedrine promotes GAP-43 and synaptophysin expression, inhibits /3 -endorphin expression in the hippocampal CA3 area, and improves motor function in rats following cerebral ischemia/reperfusion injury. Naloxone does not have the above-mentioned effects. During combined treatment with ephedrine and naloxone, however, the above-described effects are enhanced with an increased dose of naloxone. The combination of ephedrine （1.5 mg/kg/d） and naloxone （0.3 mg/kg/d） can produce optimal therapeutic efficacy in treatment of cerebral ischemic injury.

Attenuation characteristics of impact-induced seismic wave in deep tunnels:An in situ investigation based on pendulum impact test

The radiated seismic energy is an important index for the intensity assessment of microseismic(MS)events and the early warning of dynamic disasters.However,the energy of MS signals is significantly attenuated due to the heterogeneity and viscous damping of rock media.Therefore,the study on attenuation characteristics of MS signals in underground engineering has practical significance for the accurately estimation of radiated seismic energy.Based on a pendulum impact test facility and MS monitoring system,an in situ investigation was carried out to explore attenuation characteristics at a deep tunnel.The results show that the seismic energy and peak particle velocity(PPV)attenuation are exponentially related to the propagation distance.The attenuation coefficient of energy is larger than that of PPV.With the increase in the input impact-energy,the seismic energy attenuation coefficient decreases as a power function.An empirical relationship between energy attenuation coefficient and wave impedance of rock mass was established in this scenario.Moreover,the time-frequency characteristics and energy distribution laws of impact-induced signals were investigated by the continuous wavelet transform(CWT)and wavelet packet analyses,respectively.The dominant frequency of signals decreases gradually as the propagation distance increases.Based on the energy attenuation characteristics,a new method was proposed to calculate the released source energy of MS events in the field.This study can provide an insight into energy attenuation characteristics of seismic waves and references for attenuation correction in seismic energy calculation.

PTEN induces anoikis through its phosphatase activity in human bladder transitional carcinoma cells BIU-87

Objective:To investigate the effects and mechanisms of tumor suppressor gene PTEN on the induction of anoikis of human bladder transitional carcinoma cells BIU-87.Methods:BIU-87 cells were transfected with GFP plasmids containing wild-type PTEN or phosphatase inactivating mutant PTEN(C124A-PTEN)in vitro.The PTEN expression and the phosphorylation levels of focal adhesion kinase(FAK)and protein kinase B(PKB/Akt)were detected by Western blotting.Flow cytometry assay and laser scanning confocal microscopy were used to analyze apoptosis in adherent and non-adherent cells.Results: Compared with the control group,PTEN expression in the cells transfected with wild-type PTEN increased to 210%–260%, while the phosphorylation level of FAK and Akt decreased 59%(P<0.01)and 89%(P<0.01),respectively.And the anoikis percentage increased from 8.32±0.57%to 37.62±2.12%.In the cells transfected with C124A-PTEN,neither the phos- phorylation of FAK and Akt nor the anoikis percentage had obviously changed,although the PTEN expression enhanced remarkably in comparison with the control.Conclusion:Through its phosphatase activity,tumor suppressor gene PTEN can suppress the phosphorylation of FAK and Akt,and induce anoikis in human bladder transitional carcinoma cells BIU-87.

Performance Prediction of Switched Reluctance Motor using Improved Generalized Regression Neural Networks for Design Optimization

Since practical mathematical model for the design optimization of switched reluctance motor(SRM)is difficult to derive because of the strong nonlinearity,precise prediction of electromagnetic characteristics is of great importance during the optimization procedure.In this paper,an improved generalized regression neural network(GRNN)optimized by fruit fly optimization algorithm(FOA)is proposed for the modeling of SRM that represent the relationship of torque ripple and efficiency with the optimization variables,stator pole arc,rotor pole arc and rotor yoke height.Finite element parametric analysis technology is used to obtain the sample data for GRNN training and verification.Comprehensive comparisons and analysis among back propagation neural network(BPNN),radial basis function neural network(RBFNN),extreme learning machine(ELM)and GRNN is made to test the effectiveness and superiority of FOA-GRNN.