Theory,technology and application of grouted bolting in soft rock roadways of deep coal mines

The grouted bolt,combining rock bolting with grouting techniques,provides an effective solution for controlling the surrounding rock in deep soft rock and fractured roadways.It has been extensively applied in numerous deep mining areas characterized by soft rock roadways,where it has demonstrated remarkable control results.This article systematically explores the evolution of grouted bolting,covering its theoretical foundations,design methods,materials,construction processes,monitoring measures,and methods for assessing its effectiveness.The overview encompassed several key elements,delving into anchoring theory and grouting reinforcement theory.The new principle of high pretensioned high-pressure splitting grouted bolting collaborative active control is introduced.A fresh method for dynamic information design is also highlighted.The discussion touches on both conventional grouting rock bolts and cable bolts,as well as innovative grouted rock bolts and cables characterized by their high pretension,strength,and sealing hole pressure.An examination of the merits and demerits of standard inorganic and organic grouting materials versus the new inorganic–organic composite materials,including their specific application conditions,was conducted.Additionally,the article presents various methods and instruments to assess the support effect of grouting rock bolts,cable bolts,and grouting reinforcement.Furthermore,it provides a foundation for understanding the factors influencing decisions on grouted bolting timing,the sequence of grouting,the pressure applied,the volume of grout used,and the strategic arrangement of grouted rock bolts and cable bolts.The application of the high pretensioned high-pressure splitting grouted bolting collaborative control technology in a typical kilometer-deep soft rock mine in China—the soft coal seam and soft rock roadway in the Kouzidong coal mine,Huainan coal mining area,was introduced.Finally,the existing problems in grouted bolting control technology for deep soft rock roadways are analyzed,and the future development trend of grouted bolting control technology is anticipated.

Failure mechanism and simulation for long run-out of the catastrophic rock landslide in the Shanyang Vanadium Mine,China

On 12th August 2015,a massive rapid long run-out rock landslide occurred in the Shanyang Vanadium Mine in Shaanxi Province,China,which claimed the lives of 65 miners.No heavy rainfalls,earthquakes,and mining blasts were recorded before the incident.Therefore,the failure mechanism and the cause of the long run-out movement are always in arguments.In this paper,we conducted a detailed field investigation,laboratory tests,block theory analysis,and numerical simulation to investigate the failure and long run-out mechanisms of the landslide.The field investigation results show that the source material of the rock landslide is a huge dolomite wedge block bedding on siliceous shale layers.Uniaxial compression tests indicate that the uniaxial compression strength of the intact dolomite is 130-140MPa and the dolomite shows a brittle failure mode.Due to the progressive downward erosion of the gully,the dolomite rock bridge at the slope toe became thinner.As the compression stress in the dolomite bridge increased to surpass its strength,the brittle failure of the bridge occurred.Then huge potential energy was released following the disintegration of the landslide,which led to the high acceleration of this rock landslide.The 3D discrete element simulation results suggest that the low intergranular friction contributes to the long run-out movement of this rock landslide.

Energy mechanism of bolt supporting effect to fissured rock under static and dynamic loads in deep coal mines

The stability control of fissured rock is difficult,especially under static and dynamic loads in deep coal mines.In this paper,the dynamic mechanical properties,strain rate evolution and energy dissipation of fissured and anchored rocks were respectively obtained by SHPB tests.It was found that bolt can provide supporting efficiency-improving effect for fissured rock against dynamic disturbance,and this effect increased quadratically with decrease in anchoring angles.Then,the energy dissipation mechanism of anchored rock was obtained by slipping model.Furthermore,bolt energy-absorbing mechanism by instantaneous tensile-shear deformation was expressed based on material mechanics,which was the larger the anchoring angle,the smaller the energy absorption,and the less the contribution to supporting efficiency improvement.On this basis,the functional relationship between energy dissipation of anchored rock and energy absorption of bolt was established.Taking the coal-gangue separation system of Longgu coal mine as an example,the optimal anchoring angle can be determined as 57.5°–67.5°.Field monitoring showed fissured rock with the optimal anchoring angle,can not only effectively control the deformation,but also fully exert the energy-absorbing and efficiency-improving effect of bolt itself.This study provides guidance to the stability control and supporting design for deep engineering under the same or similar conditions.

A cleaner production strategy for acid mine drainage prevention of waste rock:A porphyry copper case

An in-process technology approach is proposed to identify the source of acid mine drainage(AMD)generation and prevent its formation in a porphyry copper waste rock(WR).Adopting actions before stockpiling the WR enables the establishment of potential contaminants and predicts the more convenient method for AMD prevention.A WR sample was separated into size fractions,and the WR’s net acidgenerating potential was quantified using chemical and mineralogical characterization.The diameter of physical locking of sulfides(DPLS)was determined,and the fractions below the DPLS were desulfurized using flotation.Finally,the WR fractions and tailing from the flotation test were submitted to acid-base accounting and weathering tests to evaluate their acid-generating potential.Results show that the WR’s main sulfide mineral is pyrite,and the DPLS was defined as 850μm.A sulfide recovery of 91%was achieved using a combination of HydroFloat^(®)and Denver cells for a size fraction lower than DPLS.No grinding was conducted.The results show that size fractions greater than DPLS and the desulfurized WR are unlikely to produce AMD.The outcomes show that in-processing technology can be a more proactive approach and an effective tool for avoiding AMD in a porphyry copper WR.

Prediction of rock fragmentation in a fiery seam of an open-pit coal mine in India

Spontaneous combustion of coal increases the temperature in adjoining overburden strata of coal seams and poses a challenge when loading blastholes.This condition,known as hot-hole blasting,is dangerous due to the increased possibility of premature explosions in loaded blastholes.Thus,it is crucial to load the blastholes with an appropriate amount of explosives within a short period to avoid premature detonation caused by high temperatures of blastholes.Additionally,it will help achieve the desired fragment size.This study tried to ascertain the most influencial variables of mean fragment size and their optimum values adopted for blasting in a fiery seam.Data on blast design,rock mass,and fragmentation of 100 blasts in fiery seams of a coal mine were collected and used to develop mean fragmentation prediction models using soft computational techniques.The coefficient of determination(R^(2)),root mean square error(RMSE),mean absolute error(MAE),mean square error(MSE),variance account for(VAF)and coefficient of efficiency in percentage(CE)were calculated to validate the results.It indicates that the random forest algorithm(RFA)outperforms the artificial neural network(ANN),response surface method(RSM),and decision tree(DT).The values of R^(2),RMSE,MAE,MSE,VAF,and CE for RFA are 0.94,0.034,0.027,0.001,93.58,and 93.01,respectively.Multiple parametric sensitivity analyses(MPSAs)of the input variables showed that the Schmidt hammer rebound number and spacing-to-burden ratio are the most influencial variables for the blast fragment size.The analysis was finally used to define the best blast design variables to achieve optimum fragment size from blasting.The optimum factor values for RFA of S/B,ld/B and ls/ld are 1.03,1.85 and 0.7,respectively.

贝母素乙调节RhoA/ROCK信号通路对膝骨关节炎大鼠软骨损伤的影响

目的 探讨贝母素乙调节Ras同源基因家族成员A(RhoA)/Rho相关的卷曲螺旋激酶(ROCK)信号通路对膝骨关节炎(knee osteoarthritis, KOA)大鼠软骨损伤的影响。方法 以碘乙酸钠(MIA)法制备KOA大鼠模型,随机分为模型组、贝母素乙(3.5 mg/kg)组、贝母素乙(3.5 mg/kg)+LPA(RhoA激活剂,1 mg/kg)组,每组10只,另选10只大鼠为对照组。机械刺激法和热辐射法检测大鼠膝关节疼痛症状;检测大鼠关节肿胀度、膝关节宽度并以步态评分评测其关节功能;透射电镜检测大鼠膝关节软骨细胞超微结构;TUNEL染色检测大鼠关节软骨细胞凋亡比;酶联免疫吸附(ELISA)法检测大鼠血清和关节液促炎因子白细胞介素(IL)-18、单核细胞趋化蛋白1(MCP-1)水平;免疫印迹检测各组大鼠关节软骨组织凋亡(Cleaved caspase-3、Bax)和RhoA/ROCK通路相关蛋白表达。结果 贝母素乙可降低KOA大鼠关节肿胀度、膝关节宽度、步态评分、软骨细胞凋亡比、血清及关节液IL-18、MCP-1水平、软骨组织Cleaved caspase-3、Bax、RhoA、ROCK1、ROCK1蛋白表达,升高机械痛阈值、热痛阈值(P<0.05);LPA可减弱贝母素乙对KOA大鼠关节软骨损伤的改善作用。结论 贝母素乙可通过抑制RhoA/ROCK信号激活而抑制KOA大鼠关节炎症反应和关节软骨细胞凋亡,减轻软骨损伤。

桃叶珊瑚苷调节RhoA/ROCK信号通路对胶质母细胞瘤细胞活力和上皮间质转化的影响

[目的]研究桃叶珊瑚苷(AU)对胶质母细胞瘤(GBM)细胞活力和上皮间质转化(EMT)的影响,并对其作用机制进行探讨。[方法]将U87细胞随机分为对照组、AU低浓度组、AU中浓度组、AU高浓度组、Y-27632组、AU高浓度+Y-27632组。细胞计数器试剂盒(CCK-8)法检测细胞活力,流式细胞术检测细胞凋亡,Transwell小室实验检测细胞迁移和侵袭,蛋白免疫印迹法(Western Blot)检测基质金属蛋白酶(MMP)2、MMP9、波形蛋白(Vimentin)、上皮钙黏蛋白(E-cadherin)、神经钙黏蛋白(N-cadherin)、Ras同源基因家族成员A(RhoA)、Rho相关卷曲螺旋蛋白激酶(ROCK)1、ROCK2表达。构建GBM裸鼠模型,随机分为裸鼠对照组、AU组、Y-27632组、AU+Y-27632组,测量肿瘤质量与体积,免疫组化法检测移植瘤组织RhoA、ROCK1、ROCK2蛋白表达。[结果]GBM细胞活力随着AU浓度的升高而逐渐降低(P<0.05),选择U87作为后续实验细胞,选择10、25、50μmol/L浓度作为AU后续实验浓度。与对照组比较,AU低、中、高浓度组和Y-27632组细胞活力、迁移和侵袭细胞数、MMP2、MMP9、N-cadherin、Vimentin、RhoA、ROCK1、ROCK2表达显著下降,凋亡率、E-cadherin表达显著升高(P<0.05),其中高浓度AU和Y-27632组共同处理的细胞变化更显著(P<0.05)。AU和Y-27632均能抑制移植瘤质量和体积,降低RhoA/ROCK信号通路蛋白表达(P<0.05)。[结论]AU能抑制GBM细胞活力、迁移侵袭和EMT,促进细胞凋亡,其作用机制可能与抑制RhoA/ROCK信号通路有关。

SLC9A3-AS1调控miR-148a-3p/ROCK1信号轴影响肾癌细胞生物学功能

目的检测lncRNA SLC9A3-AS1在肾透明细胞癌(clear cell renal cell carcinoma,ccRCC)组织与肾癌细胞中的表达水平,探讨其促进肾癌细胞恶性生物学行为的机制。方法应用GEPIA2在线软件(http://gepia2.cancer-pku.cn/)分析TCGA数据库中SLC9A3-AS1在ccRCC组织中的表达水平;采用实时荧光定量聚合酶链反应(qRT-PCR)检测SLC9A3-AS1在不同肾癌细胞系、24例ccRCC组织与癌旁正常肾脏组织中的表达水平;应用细胞增殖/毒性检测试剂盒(cell counting kit-8,CCK-8)和Transwell小室迁移实验检测敲低SLC9A3-AS1表达对肾癌细胞增殖与迁移的影响;应用蛋白质免疫印迹法检测增殖与迁移相关信号通路蛋白的表达水平;采用双荧光素酶报告基因实验验证SLC9A3-AS1与miR-148a-3p/ROCK1轴的靶向调控关系。结果GEPIA2软件分析结果显示,相较正常肾脏组织,SLC9A3-AS1在肾透明细胞癌组织中表达显著上调(P<0.01)。qRT-PCR结果显示,相较癌旁正常肾脏组织,SLC9A3-AS1在24例ccRCC组织中表达显著上调(P<0.01);相较永生化肾小管上皮细胞,SLC9A3-AS1在4种肾癌细胞系中表达均显著上调,以786-O细胞最为显著(P<0.01)。干扰SLC9A3-AS1表达,可显著抑制786-O细胞的增殖与迁移能力,上调E-cadherin的蛋白表达水平,而下调N-cadherin、MMP2的蛋白表达水平(均P<0.05);过表达miR-148a-3p可显著抑制786-O细胞的增殖与迁移能力(P<0.01)。双荧光素酶报告基因检测结果表明,SLC9A3-AS1可特异性结合miR-148a-3p,后者进一步靶向结合ROCK1 mRNA的3′UTR区域;过表达miR-148a-3p可明显下调ROCK1 mRNA的表达水平,敲低miR-148a-3p表达则产生相反的效应;敲低SLC9A3-AS1表达可显著下调786-O细胞中ROCK1 mRNA与蛋白的表达水平(P<0.01);下调miR-148a-3p表达可部分逆转SLC9A3-AS1沉默对786-O细胞增殖与迁移的抑制作用(P<0.05)。结论SLC9A3-AS1在ccRCC中通过调控miR-148a-3p/ROCK1轴发挥促癌作用,有望成为ccRCC的一个新的分子标志物。

芍药苷调节RhoA/ROCK信号通路对实验性自身免疫性葡萄膜炎小鼠Th17/Treg免疫平衡的影响

目的探讨芍药苷调节Ras同源基因家族蛋白A(RhoA)/Rho相关卷曲螺旋形成蛋白激酶(ROCK)信号通路对实验性自身免疫性葡萄膜炎(experimental autoimmune uveitis,EAU)小鼠辅助性T淋巴细胞17(Th17)/调节性T细胞(Treg)免疫平衡的影响。方法随机选出10只小鼠作为正常对照组,其余小鼠构建EAU模型,将造模成功小鼠随机平分为模型组、芍药苷组(10 mg·kg^(-1)芍药苷)、RhoA/ROCK信号通路激活剂溶血磷脂酸(LPA)组(25μmol·L^(-1)LPA)、芍药苷+LPA组(10 mg·kg^(-1)芍药苷+25μmol·L^(-1)LPA),每组10只。模型组和正常对照组给予等量生理盐水,给药每天1次,持续14 d。眼前节临床表现评分评估炎症严重程度;HE染色观察眼球组织病理形态;ELISA法检测血清中炎性因子转化生长因子-β(trarsforming growth factor beta,TGF-β)、白细胞介素10(IL-10)、白细胞介素17(IL-17)、白细胞介素23(IL-23)水平;流式细胞术检测脾脏Th17/Treg细胞水平;Western Blot法检测维甲酸相关核孤儿受体γt(RORγt)、叉头状转录因子3(Foxp3)以及RhoA/ROCK信号通路蛋白表达。结果正常对照组小鼠无虹膜、结膜血管舒张充血,与正常对照组比,模型组小鼠出现虹膜血管舒张充血,前房、虹膜、睫状体和视网膜内均有大量炎性细胞膨胀,眼前节临床表现评分、IL-17和IL-23含量、Th17细胞水平、Th17/Treg、RORγt、RhoA、ROCK1蛋白水平明显升高(P<0.05),IL-10和TGF-β含量、Treg细胞水平、Foxp3水平明显下降(P<0.05)。与模型组比,芍药苷组小鼠虹膜血管充血症状明显缓解,眼前节临床表现评分、IL-17和IL-23含量、Th17细胞水平、Th17/Treg、RORγt、RhoA、ROCK1蛋白水平明显降低(P<0.05),IL-10和TGF-β含量、Treg细胞水平、Foxp3水平明显升高(P<0.05);而LPA加重了眼部损伤(P<0.05),逆转了芍药苷对EAU小鼠的改善效果(P<0.05)。结论芍药苷可通过下调RhoA/ROCK信号通路调节EAU小鼠Th17/Treg免疫平衡减轻EAU小鼠葡萄膜炎。

艾灸联合保真汤加减治疗糖尿病肾病的疗效观察及对CT灌注参数、Rho/ROCK信号通路蛋白的影响

目的 观察艾灸联合保真汤加减治疗糖尿病肾病气阴两虚证的临床疗效及对CT灌注参数、Rho/ROCK信号通路蛋白的影响。方法 将146例糖尿病肾病气阴两虚证患者随机分为观察组(74例)和对照组(72例)。在对症治疗的基础上,对照组给予厄贝沙坦片,观察组给予艾灸联合保真汤加减。观察两组中医主症积分、CT灌注参数[血尿素氮(blood urea nitrogen, BUN)、血肌酐(serum creatinine, SCr)、尿白蛋白排泄率(urinary albumin excretion rate, UAER)和24 h尿蛋白定量(24-hour urinary protein quantification, 24 h Upro)]、肾血流指标[舒张末期血流速度(end-diastolic velocity, EDV)、肾段动脉的收缩期峰值流速(peak-systolic velocity, PSV)、搏动指数(pulsatility index, PI)和阻力指数(resistive index, RI)]、血清炎性因子[肿瘤坏死因子-α(tumor necrosis factor-α, TNF-α)、白细胞介素-1β(interleukin-1β, IL-1β)、白细胞介素-6(interleukin-6, IL-6)和C反应蛋白(C-reactive protein, CRP)]水平及Rho/ROCK信号通路[Ras同源基因家族成员A(Ras homolog gene family member A, RhoA)、Rho关联含卷曲螺旋蛋白激酶Ⅰ(Rho-associated coiled-coil containing protein kinaseⅠ, ROCKI)、α-平滑肌肌动蛋白(α-smooth muscle actin, α-SMA)和钙黏附蛋白-E(E-cadherin, E-Cad)]蛋白水平,并比较两组临床疗效及不良反应。结果 观察组总有效率为97.3%(72/74),明显高于对照组的81.9%(59/72)(P<0.05)。观察组治疗后中医主症积分低于治疗前和对照组(P<0.05)。两组治疗后CT灌注参数降低(P<0.05),且观察组低于对照组(P<0.05)。观察组治疗后PSV、EDV较治疗前和对照组加快(P<0.05),RI、PI较治疗前和对照组降低(P<0.05)。观察组治疗后血清炎性因子水平较治疗前和对照组降低(P<0.05)。观察组治疗后Rho A、ROCKI、α-SMA蛋白水平较治疗前和对照组降低(P<0.05),E-Cad蛋白水平较治疗前和对照组升高(P<0.05)。观察组不良反应发生率为1.4%(1/74),低于对照组的19.4%(14/72)(P<0.05)。结论 在对症治疗的基础上,艾灸联合保真汤加减可明显提高糖尿病肾病气阴两虚证患者的治疗效果,其机制可能与改善CT灌注参数,调节血清Rho/ROCK信号通路蛋白相关。

黄芩苷通过ROS依赖性调节RhoA/ROCK通路保护氯化钴诱导心肌细胞损伤的实验研究

目的:本研究旨在探讨黄芩苷(Baicalin)对氯化钴(CoCl_(2))诱导H9c2心肌细胞缺氧损伤的作用机制。方法:采用CoCl_(2)建立心肌细胞缺氧损伤模型,并分别加入不同浓度的黄芩苷培养。将正常氧培养设置为对照组,CoCl_(2)培养H9c2心肌细胞设置为CoCl_(2)组;Baicalin、Y27632(Rho激酶抑制剂)预处理的H9c2缺氧心肌细胞设置为CoCl_(2)+Baicalin组、CoCl_(2)+Y27632组、CoCl_(2)+Baicalin+Y27632组。通过细胞毒性检测试剂盒(CCK8)检测细胞活性;荧光探针测定细胞中活性氧(ROS)的表达;WST-8检测心肌细胞超氧化歧化酶(SOD)活力;TBA法测定丙二醇(MDA)浓度;同时采用WesternBlot方法分析RhoA、ROCK1、ROCK2、TNF-α、IL-1β蛋白表达情况。结果:处理H9c2细胞24 h后,1 000μmol/L的CoCl_(2)和75μmol/L黄芩苷对治疗心肌细胞缺氧损伤具有较好的细胞活力。CoCl_(2)组细胞活性明显低于对照组,加入黄芩苷后可显著提高细胞活性(P<0.05);与对照组相比,CoCl_(2)组心肌细胞可上调ROS、MDA表达,下调SOD活力,升高RhoA、ROCK1、ROCK2、TNF-α、IL-1β蛋白表达水平,加入Baicalin后可逆转上诉蛋白的表达水平;与CoCl_(2)组相比,CoCl_(2)+Baicalin可抑制ROS、MDA的表达,上调SOD含量,下调RhoA、ROCK1、ROCK2、TNF-α、IL-1β蛋白表达水平,而加入Y27632(Rho激酶抑制剂)后则可显著增强Baicalin带来的保护作用。结论:Baicalin可减轻CoCl_(2)诱导H9c2心肌细胞缺氧损伤的炎症、氧化应激反应,其机制与抑制ROS依赖性RhoA/ROCK通路有关。

川芎嗪抑制ROCK的表达降低模拟失重大鼠血管Ca^(2+)敏感性

研究失重条件下血管平滑肌收缩性、Ca^(2+)敏感性及其调控通路RhoA-ROCK蛋白表达的变化,以及川芎嗪干预对其的影响。大鼠尾部悬吊模拟失重,在机体前、后部分别选取颈总动脉和肠系膜上动脉。在模拟失重大鼠颈总动脉中,由苯肾上腺素(PHE)或KCl诱发的血管收缩性和Ca^(2+)敏感性增强,RhoA激酶2(ROCK II)的表达、肌球蛋白磷酸酶靶亚基1(MYPT1)和肌球蛋白调节轻链(MLC)的磷酸化水平均上升,血管孵育Y-27632(ROCK特异性抑制剂)后可降低以上变化。模拟失重大鼠灌饲川芎嗪亦可降低以上变化。模拟失重后,大鼠肠系膜上动脉的收缩性和Ca^(2+)敏感性、ROCK II的表达、MYPT1和MLC的磷酸化水平降低,血管孵育Y-27632对以上变化无明显作用。模拟失重大鼠灌饲川芎嗪亦对以上变化无明显作用。结果表明,由RhoA-ROCK调控的血管平滑肌Ca^(2+)敏感性的变化可能是失重条件下机体前后部血管收缩性发生区域性重塑的关键因素。川芎嗪可抑制ROCK蛋白的表达,降低血管平滑肌升高的Ca^(2+)敏感性,从而纠正失重条件下机体前部血管收缩性的增强,但对失重条件下机体后部血管收缩性的减弱无恢复作用。

Mineralogy,microstructures and geomechanics of rock salt for underground gas storage

Rock salt has excellent properties for its use as underground leak‐proof containers for the storage of renewable energy.Salt solution mining has long been used for salt mining,and can now be employed in the construction of underground salt caverns for the storage of hydrogen gas.This paper presents a wide range of methods to study the mineralogy,geochemistry,microstructure and geomechanical characteristics of rock salt,which are important in the engineering of safe underground storage rock salt caverns.The mineralogical composition of rock salt varies and is linked to its depositional environment and diagenetic alterations.The microstructure in rock salt is related to cataclastic deformation,diffusive mass transfer and intracrystalline plastic deformation,which can then be associated with the macrostructural geomechanical behavior.Compared to other types of rock,rock salt exhibits creep at lower temperatures.This behavior can be divided into three phases based on the changes in strain with time.However,at very low effective confining pressure and high deviatoric stress,rock salt can exhibit dilatant behavior,where brittle deformation could compromise the safety of underground gas storage in rock salt caverns.The proposed review presents the impact of purity,geochemistry and water content of rock salt on its geomechanical behavior,and thus,on the safety of the caverns.

Failure mechanism and control countermeasures of surrounding rock at deep large section chamber intersection in the Wanfu Coal Mine

In order to solve the problem of large deformation at the intersection of deep large section soft rock roadway,this paper takes the intersection of kilometer-deep roadway in the Wanfu Coal Mine as an engineering example and applies Negative Poisson’s Ratio(NPR)steel anchor cable in roadway support for the first time.By combining numerical simulation indoor test,theoretical analysis and field test,the deformation mechanism of surrounding rock at the intersection of deep-buried roadway was analyzed,and the control strategy with micro NPR steel anchor cable as the core was put forward.Through numerical simulation,the numerical analysis model of roadway intersection with different intersection angles and excavation sequence was constructed,and the impact of two key variables of rake angle and excavation sequence on the stability of surrounding rock at roadway intersection was studied.The optimal dip angle is 90°and the optimal excavation sequence was determined as pump house-pump house passage-substation.The mechanical properties of the micro-NPR steel anchor cable were studied through the static tensile test in the laboratory.The results showed that the micro-NPR steel anchor cable showed high constant resistance,uniform tensile,no yield platform,and no obvious necking phenomenon during breaking.Through theoretical derivation,it was calculated that the vertical stress of roadway intersection is 45 MPa,and the bearing capacity of superposed arch composed of micro NPR steel anchor cable is 1257 kN,which is enough to guarantee the overall stability of intersection.Support application test and monitoring were carried out on site,and it was verified that the combined support strategy of short and long micro NPR steel anchor cable has a good control effect on large deformation of surrounding rock at intersection,which provides a new support material and support means for the safety and stabilization control of surrounding rock at intersection.

益母草碱调节RhoA/ROCK信号通路对冠心病大鼠主动脉内皮细胞损伤的影响

目的:研究益母草碱(Leo)通过调节Ras同源基因家族成员A(RhoA)/Rho相关的卷曲螺旋激酶(ROCK)信号通路对冠心病(CHD)大鼠主动脉内皮细胞损伤的影响及机制。方法:将造模成功的75只CHD大鼠随机分为模型组(CHD组)、Leo低、中、高剂量组(Leo-L组、Leo-M组、Leo-H组)和Leo高剂量组+RhoA激活剂LPA组(Leo-H+LPA组),每组15只。Leo-L、Leo-M、Leo-H组分别灌胃15、30、60mg·kg^(-1)·d^(-1)的Leo,Leo-H+LPA组灌胃60mg·kg^(-1)·d^(-1)的Leo,另需腹腔注射1mg·kg^(-1)·d^(-1)的LPA,Control组和CHD组以相同方式给予等量生理盐水,均连续干预4周。超声心动图测定心功能指标;全自动生化分析仪测定总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)水平;酶联免疫吸附测定(ELISA)检测白细胞介素6(IL-6)、肿瘤坏死因子α(TNF-α)、一氧化氮(NO)、内皮素1(ET-1)、内皮细胞特异性分子-1(EMS1)、血管内皮细胞粘附分子1(VCAM-1)水平;苏木精-伊红(HE)染色观察主动脉内皮损伤;流式细胞仪检测主动脉内皮细胞凋亡;免疫印迹法(Western blot)检测RhoA/ROCK信号通路相关蛋白表达。结果:与Control组相比,CHD组主动脉壁增厚且染色不均匀,细胞膨大,排列紊乱,内皮粗糙;左室舒张末期内径(LVEDD)、左室收缩末期内径(LVESD)、TC、TG、LDL-C、IL-6、TNF-α、ET-1、VCAM-1和EMS1水平、细胞凋亡率及RhoA、ROCK1和ROCK2蛋白表达显著升高(P<0.05),左室射血分数(LVEF)、缩短分数(FS)、HDL-C、NO水平显著降低(P<0.05)。与CHD组相比,Leo-L组、Leo-M组、Leo-H组主动脉染色均匀,动脉壁结构清晰,细胞排列紧密且形态较正常,内膜较平滑;LVEDD、LVESD、TC、TG、LDL-C、IL-6、TNF-α、ET-1、VCAM-1和EMS1水平、细胞凋亡率及RhoA、ROCK1和ROCK2蛋白表达逐渐降低(P<0.05),LVEF、FS、HDL-C、NO水平逐渐升高(P<0.05)。Leo-H+LPA组逆转了Leo对CHD大鼠的保护作用(P<0.05)。结论:Leo可能通过抑制RhoA/ROCK信号通路改善CHD大鼠心功能,降低血脂,抑制炎症,进而减轻CHD大鼠主动脉内皮细胞损伤。

苍术素调节RhoA/ROCK信号通路对弥漫大B细胞淋巴瘤细胞恶性生物学行为的影响

目的:探讨苍术素(ATR)调节Ras同源基因家族成员A(RhoA)/Rho相关卷曲螺旋形成蛋白激酶(ROCK)信号通路对弥漫大B细胞淋巴瘤(DLBCL)细胞恶性生物学行为的影响。方法:常规培养DLBCL细胞SUDHL-4,将其随机分为对照组、低浓度ATR组(ATR-L组,5μmol/L ATR)、中浓度ATR组(ATR-M组,10μmol/L ATR)、高浓度ATR组(ATR-H组,20μmol/L ATR)和高浓度ATR+RhoA激活剂U46619组(ATR+U46619组,20μmol/L ATR+10 nmol/L U46619)。CCK-8法测定细胞增殖活性。划痕实验检测细胞迁移能力。Transwell实验测定细胞侵袭能力。流式细胞术检测细胞凋亡率。实时荧光定量PCR(RT-qPCR)法测定细胞中RhoA、ROCK1 mRNA表达。免疫印迹法(Western blot)测定各组细胞B细胞淋巴瘤-2(Bcl-2)、Bcl-2相关X蛋白(Bax)、RhoA、ROCK1蛋白表达。结果:与对照组比较,ATR-M组、ATR-H组SUDHL-4细胞OD450值(48、72 h)、细胞迁移率、细胞侵袭数目、RhoA、ROCK1 mRNA和蛋白表达、Bcl-2蛋白表达降低,细胞凋亡率、Bax蛋白表达升高(均P<0.05)。RhoA激活剂U46619减弱了ATR对DLBCL细胞恶性生物学行为的抑制作用。结论:ATR可能通过下调RhoA/ROCK信号通路抑制DLBCL细胞恶性生物学行为。

抑制Rho/ROCK通路对气道平滑肌细胞增殖与迁移的影响及相关机制

目的研究抑制Ras同源基因(Ras homolog gene,Rho)/Rho相关卷曲螺旋形成蛋白激酶(Rhoassociated coiled-coil forming protein kinase,ROCK)通路对心肌素(myocardin,MYOCD)参与的气道平滑肌细胞增殖与迁移的影响及分子机制。方法体外构建腺病毒载体Ad-ZsGreen-shRNA-hROCK1感染人气道平滑肌细胞,将细胞随机分为4组:ROCK1基因沉默对照(shNC)组、shNC+花生四烯酸(arachidonic acid,AA;Rho/ROCK通路激活剂)组、ROCK1基因沉默(shROCK1)组、shROCK1+AA组(各组n=3)。采用实时荧光定量聚合酶链反应法、Western blot法检测ROCK1、MYOCD mRNA和蛋白表达水平,ELISA法检测球状肌动蛋白和丝状肌动蛋白水平,免疫荧光染色法及细胞划痕实验检测细胞增殖及迁移情况。结果与shNC+AA组相比,shROCK1+AA组ROCK1、MYOCD mRNA和蛋白表达水平降低,球状肌动蛋白、丝状肌动蛋白表达降低,细胞增殖、细胞迁移能力降低(P<0.05)。结论抑制Rho/ROCK通路致气道平滑肌细胞增殖及迁移能力受抑,其机制可能与MYOCD的下调有关.

Drilling-based measuring method for the c-φ parameter of rock and its field application

The technology of drilling tests makes it possible to obtain the strength parameter of rock accurately in situ. In this paper, a new rock cutting analysis model that considers the influence of the rock crushing zone(RCZ) is built. The formula for an ultimate cutting force is established based on the limit equilibrium principle. The relationship between digital drilling parameters(DDP) and the c-φ parameter(DDP-cφ formula, where c refers to the cohesion and φ refers to the internal friction angle) is derived, and the response of drilling parameters and cutting ratio to the strength parameters is analyzed. The drillingbased measuring method for the c-φ parameter of rock is constructed. The laboratory verification test is then completed, and the difference in results between the drilling test and the compression test is less than 6%. On this basis, in-situ rock drilling tests in a traffic tunnel and a coal mine roadway are carried out, and the strength parameters of the surrounding rock are effectively tested. The average difference ratio of the results is less than 11%, which verifies the effectiveness of the proposed method for obtaining the strength parameters based on digital drilling. This study provides methodological support for field testing of rock strength parameters.

Technical problems and non destructive testing of rock bolt support systems in mines

The problem of proper assessment of the technical functionality of rock bolt support systems is still valid.Many research centers have undertaken eforts to diagnose and monitor the technical state of such a support system used in mines and tunneling.With that aim the method of quality assessment of grouted rock bolts was invented and a relevant apparatus was constructed.The method concerns non-destructive identifcation of discontinuity of a resin layer(grout)surrounding rock bolts.The method is based on an impact excitation of a rock bolt and uses modal analysis procedures.Assuming that the installed rock bolt acts as an oscillator,diferent lengths and positions of grouting discontinuity alter its modal parameters.The extraction of these modal parameters,of which a resonant frequency is seen as the most valued,enable the relevant identifcation of grout discontinuity.After constructing a prototype version and validating the results for known cases of resin discontinuity in an experimental coal mine,the apparatus fulflling ATEX requirements was developed.Subsequently that version was also verifed both in laboratory conditions and in an experimental coal mine.As necessary for proper identifcation of discontinuity length,the reference data base was developed and elaborated consisting of a very large number of fnite element models(FE models),namely discontinuity cases.The models encountered diferent rock bolt lengths and diameters,diferent rock strata parameters and diferent positions and lengths of resin layers.Then the method was used in a working coal mine to monitor a technical state of rock bolt support system mounted to reinforce long underground openings.The data base was utilized as reference for investigated rock bolts.

Rho/ROCK通路与心律失常的研究进展

越来越多的证据表明,Rho/ROCK通路在不同程度上调控着细胞的生长、发育、迁移、增殖和死亡,并在各种疾病中发挥重要作用。此外,Rho/ROCK通路与成纤维细胞、Ca^( 2+)和炎症因子等的相互作用对肺动脉高压和心血管疾病的发生与发展产生了重要的影响。近年来Rho/ROCK通路在心律失常中发挥的作用备受关注,现通过总结相关研究,为抗心律失常药的研究提供进一步参考。