Temporomandibular joint(TMJ)disc displacement is one of the most significant subtypes of temporomandibular joint disorders,but its etiology and mechanism are poorly understood.In this study,we elucidated the mechanism...Temporomandibular joint(TMJ)disc displacement is one of the most significant subtypes of temporomandibular joint disorders,but its etiology and mechanism are poorly understood.In this study,we elucidated the mechanisms by which destruction of inflamed collagen fibrils induces alterations in the mechanical properties and positioning of the TMJ disc.By constructing a rat model of TMJ arthritis,we observed anteriorly dislocated TMJ discs with aggravated deformity in vivo from five weeks to six months after a local injection of Freund’s complete adjuvant.By mimicking inflammatory conditions with interleukin-1 beta in vitro,we observed enhanced expression of collagen-synthesis markers in primary TMJ disc cells cultured in a conventional two-dimensional environment.In contrast,three-dimensional(3D)-cultivated disc cell sheets demonstrated the disordered assembly of inflamed collagen fibrils,inappropriate arrangement,and decreased Young’s modulus.Mechanistically,inflammation-related activation of the nuclear factor kappa-B(NF-κB)pathway occurs during the progression of TMJ arthritis.NF-κB inhibition reduced the collagen fibril destruction in the inflamed disc cell sheets in vitro,and early NF-κB blockade alleviated collagen degeneration and dislocation of the TMJ discs in vivo.Therefore,the NF-κB pathway participates in the collagen remodeling in inflamed TMJ discs,offering a potential therapeutic target for disc displacement.展开更多
目的探讨Discs大同源相关蛋白5(Discs large homolog-associated protein 5,DLGAP5)在乳腺癌他莫西芬耐药性中的作用。方法通过METABRIC、TCGA、HPA、GEO等数据库分析DLGAP5在乳腺癌患者及他莫西芬治疗的乳腺癌患者或细胞系中的表达;通...目的探讨Discs大同源相关蛋白5(Discs large homolog-associated protein 5,DLGAP5)在乳腺癌他莫西芬耐药性中的作用。方法通过METABRIC、TCGA、HPA、GEO等数据库分析DLGAP5在乳腺癌患者及他莫西芬治疗的乳腺癌患者或细胞系中的表达;通过Kaplan Meier-plotter分析乳腺癌患者总体生存期(overall survival,OS)、无复发生存期(recurrence free survival,RFS)、无转移生存期(distant metastasis free survival,DMFS);通过siRNA敲低DLGAP5的表达,并运用流式细胞实验分析其对他莫西芬处理的乳腺癌细胞凋亡的影响。运用TargetScan预测靶向于DLGAP5的microRNA,并且通过UALCAN分析microRNA在乳腺癌中的表达,通过COREMINE工具进行文本挖掘分析microRNA参与DLGAP5介导乳腺癌耐药性。结果DLGAP5在乳腺癌患者及他莫西芬耐药的乳腺癌患者及细胞系中的显著升高(P<0.05),而且与患者的低OS、RFS、DMFS显著相关(P<0.05);在他莫西芬耐药细胞系中敲低DLGAP5后增加了他莫西芬诱导的癌细胞凋亡;hsa-miR-409-5p靶向于DLGAP5并且在乳腺癌患者中低表达,影响乳腺癌患者的预后;文本挖掘显示hsa-miR-409-5p与乳腺癌耐药性显著相关(P<0.05)。结论高表达DLGAP5介导乳腺癌他莫西芬耐药,而且有可能与hsa-miR-409-5p转录后调控相关。展开更多
目的:探讨Discs大同源物相关蛋白5(Discs large homolog associated protein 5,DLGAP5)在肝细胞癌(hepatocellular carcinoma,HCC)中的表达及其临床意义。方法:采用免疫组化法检测144对肝细胞癌组织和对应的癌旁组织样本中DLGAP5蛋白的...目的:探讨Discs大同源物相关蛋白5(Discs large homolog associated protein 5,DLGAP5)在肝细胞癌(hepatocellular carcinoma,HCC)中的表达及其临床意义。方法:采用免疫组化法检测144对肝细胞癌组织和对应的癌旁组织样本中DLGAP5蛋白的表达,分析其表达与患者临床病理特征的关系,绘制Kaplan-Meier生存曲线分析DLGAP5表达对患者预后的影响。结果:肝细胞癌组织中DLGAP5表达阳性率77.8%,高于癌旁组织的阳性率38.9%,差异有统计学意义(P<0.01)。DLGAP5表达与肿瘤直径、TNM分级、脉管癌栓及肿瘤包膜完整性有关(均P<0.05),而与患者性别、年龄、乙型肝炎表面抗原、肝硬化及远处转移无关(均P>0.05)。Kaplan-Meier生存曲线分析显示,DLGAP5高表达组患者总生存率显著低于DLGAP5低表达组患者,差异具有统计学意义(P<0.05)。结论:DLGAP5蛋白在肝细胞癌中表达增高,其高表达与患者的预后不良有关。展开更多
The inflammatory cytokine interleukin-1 beta （IL-1β） plays a key role in the process of intervertebral disc degenera- tion （IVDD）. In the present study, we aimed to evaluate the effect of pharmaco-serum of ＂Taor...The inflammatory cytokine interleukin-1 beta （IL-1β） plays a key role in the process of intervertebral disc degenera- tion （IVDD）. In the present study, we aimed to evaluate the effect of pharmaco-serum of ＂Taoren-Honghua-herb pair＂ on IL-1β- induced chondrocyte degeneration in vitro. Taoren （Semen persicae） and Honghua （Safflower carthamus） were administered to the rats, and the pharmaco-serum was collected and prepared. Chondrocytes of the third passage, isolated from the rat＇s vertebral endplates, were treated by standard medium only （Group NC）, IL-1β （Group IL） or combination of IL-1β and pharmaco-serum （Group TRHH）. Cell proliferation and apoptosis were determined, and the expression of aggrecan, Col2ul, Coll0ul, IL-6 and SOX9 at the mRNA level in chondrocytes was quantified by real-time PCR. Immunohistochemistry staining of type II and X collagen and Safranine O staining were also used to evaluate the chondrocytes. Compared with the Group NC, IL-1β treatment inhibited the cell proliferation and induced the cell apoptosis （P〈0.05）, and the expression of aggrecan, Col2αl and SOX9 at the mRNA level was down-regulated. In contrast, the expression of Coll0ul and IL-6 was up-regulated after IL-1β treatment （P〈0.05）. Meanwhile, the immune-staining of type II collagen and Safranine O staining were decreased, while the staining of type X collagen was increased. Compared with the Group IL, cell proliferation was increased, and apoptosis of chondrocytes was decreased when cells were treated with the pharmaco-semm of TRHH-herb pair （P〈0.05）. The expression of aggrecan, Col2cd and SOX9 at the mRNA level was up-regulated, while that of Coll0cd and IL-6 was down-regulated （P〈0.05）. Saffanine O staining also showed increased positive staining （P〈0.05）. Taken together, the treatment of pharmaco-serum of TRHH-herb pair could prevent endplate chondrocyte degeneration induced by IL-1β.展开更多
The noncarbonaceous Ediacaran discs of variable morphologies from the Jodhpur Sandstone Formation of the Marwar Supergroup, western Rajasthan, suggest different biologic affinities of plant and animal kingdom. These d...The noncarbonaceous Ediacaran discs of variable morphologies from the Jodhpur Sandstone Formation of the Marwar Supergroup, western Rajasthan, suggest different biologic affinities of plant and animal kingdom. These discs are commonly preserved on the bedding surfaces of siliciclastic sandstone and shale in strong positive relief and appear to possess a flexible to rigid body. Discs assignable to Aspidella, Cyclomedusa, Nimbia and Heimalora;all possibly inclining towards cnidarian affinity are being reported from the sandstone beds in Sursagar area. Variable morphologies among discs preserved in siliciclastic shale beds from the Artiya Kalan area support scyphozoan affinity (earlier named Marsonia from the same locality) and cnidarian affinity for small discs comparable with Funisia (considered being the first animals having sexual reproduction). Disc’s morphologies also suggest ephyra stage of Aurilia (a cnidarian form) or budding stages of some fungi, like Germinosphaera (multicellular benthic fungal fossils) and noncarbonaceous discs with well preserved wrinkles and folds like in Chuaria. Discs from the Jodhpur Sandstone, may at times display taphonomic interplay, but consistency and repetition in morphology support variable biological affinities representing diverse assemblage and advance ecosystem prevailing during Ediacaran period. A degree of genetic variability can be expected within any taxa, and this may be compounded by preservation factors affecting the Jodhpur Ediacaran discs. Sudden increase in size or gigantism is a common feature of Ediacaran life, which is evident in case of Jodhpur discs also. On the basis of fossil assemblage, the Jodhpur Group (the Marwar Supergroup) is regionally correlated with the Bhander Group of the Vindhyan Supergroup and Krol Group of Lesser Himalaya. Globally, the assemblage is comparable with the Long Mynd Group, Shropshire, UK, Fermuse Formation Newfoundland, South Australia, Russia and Norway.展开更多
The present research is focused on the numerical crack coalescence analysis of the micro-cracks and cracks produced during the cutting action of TBM disc cutters. The linear elastic fracture mechanics(LEFM) concepts a...The present research is focused on the numerical crack coalescence analysis of the micro-cracks and cracks produced during the cutting action of TBM disc cutters. The linear elastic fracture mechanics(LEFM) concepts and the maximum tangential stress criterion are used to investigate the micro crack propagation and its direction underneath the excavating discs. A higher order displacement discontinuity method with quadratic displacement discontinuity elements is used to estimate the stress intensity factors near the crack tips. Rock cutting mechanisms under single and double type discs are simulated by the proposed numerical method.The main purposes of the present modeling are to simulate the chip formation process of indented rocks by single and double discs.The effects of specific disc parameters(except speed) on the thrust force Ft, the rolling force Fr, and the specific energy ES are investigated. It has been shown that the specific energy(energy required to cut through a unit volume of rock) of the double disc is less than that of the single disc. Crack propagation in rocks under disc cutters is numerically modeled and the optimum ratio of disc spacing S to penetration depth Pd(i.e. S/Pd ratio) of about 10 is obtained, which is in good agreement with the theoretical and experimental results cited in the literature.展开更多
An internal failure mode for a soil-nailed system consists of failure at nail heads,slope facing,nail strength,along groutesoil interface and pullout failure.A better understanding of pullout of soil nail thus becomes...An internal failure mode for a soil-nailed system consists of failure at nail heads,slope facing,nail strength,along groutesoil interface and pullout failure.A better understanding of pullout of soil nail thus becomes important to assess the stability of a soil-nailed system.In the present study,an investigation into the pullout behaviour of soil nail with circular discs along the shaft has been carried out by a threedimensional finite element analysis using Abaqus/Explicit routine.A total of 67 simulations have been performed to accurately predict the pullout behaviour of soil nail.The soil nail under study has circular discs along its shaft varying in numbers from 1 to 4.The pullout of this soil nail in a pullout test box has been simulated with a constant overburden pressure of 20 kPa acting on the nail.The pullout load edisplacement characteristics,stresses around soil nail and failure mechanism during pullout are studied.Variations of dimensionless factors such as normalised pullout load factor and bearing capacity factor have been obtained with different combinations of parameters in terms of relative disc spacing ratio,anchorage length ratio,embedment ratio,diameter ratio and displacement ratio.From the results of analyses,it is found that nail with more circular discs requires higher pullout load.There are critical relative disc spacing ratio and diameter ratio which significantly affect the pullout behaviour of nail.展开更多
A 200-second X-ray quasi-periodicity in the 2-8 ke V band from Swift J1644+57 was found by Reis et al.From the onset time of quasi-periodic oscillation(QPO),we show that Swift J1644+57 is a plunging event.This QPO may...A 200-second X-ray quasi-periodicity in the 2-8 ke V band from Swift J1644+57 was found by Reis et al.From the onset time of quasi-periodic oscillation(QPO),we show that Swift J1644+57 is a plunging event.This QPO may be related to discrete clumps from the accretion disk falling into a supermassive black hole,then the outflow in the jet may be also discontinuous.We estimate the lifetime of clumps to be about several hundreds seconds and the fraction of clumpy ejecta to be about 30% from the QPO.The other possible model involves the interface between the inflow and jet magnetosphere in the magnetically choked accretion flow.Theory and numerical simulations indicate that a magnetic Rayleigh-Taylor and Kelvin-Helmholtz unstable magnetospheric interface can produce a jet-disk QPO mechanism.This event may be the first evidence of jet-disk QPO.From observations,the two models are comparable.展开更多
When the techniques of integrating the variation of the conventional DVD,the high-density multilevel run-length pit depth and width simultaneously are adopted to limited read-only optical storage method is achieved. T...When the techniques of integrating the variation of the conventional DVD,the high-density multilevel run-length pit depth and width simultaneously are adopted to limited read-only optical storage method is achieved. The dynamic range of readout signal is greatly enlarged in comparison with keeping one parameter varied, and the recording levels number can be obviously increased. The discs can be manufactured using standard photoresist mastering and replication techniques with great compatibility to conventional binary read-only discs. Experimental results show that eight-level read-only optical disc can be realized and the capacity can be increased to 20 GB.展开更多
We propose that sub-Keplerian accretion belts around stars might launch jets. The sub-Keplerian inflow does not form a rotationally supported accretion disk, but it rather reaches the accreting object from a wide soli...We propose that sub-Keplerian accretion belts around stars might launch jets. The sub-Keplerian inflow does not form a rotationally supported accretion disk, but it rather reaches the accreting object from a wide solid angle. The basic ingredients of the flow are a turbulent region where the accretion belt interacts with the accreting object via a shear layer, and two avoidance regions on the poles where the accretion rate is very low. A dynamo that is developed in the shear layer amplifies magnetic fields to high values. It is likely that the amplified magnetic fields form polar outflows from the avoidance regions. Our speculative belt-launched jets model has implications on a rich variety of astrophysical objects, from the removal of common envelopes to the explosion of core collapse supernovae by jittering jets.展开更多
Ediacaran discs from the Jodhpur Sandstone of the Marwar Supergroup, Rajasthan, exhibit a wide size ranging from a few millimetres to 75 cm in diameter. Exceptionally large size of the discs in these rocks represent t...Ediacaran discs from the Jodhpur Sandstone of the Marwar Supergroup, Rajasthan, exhibit a wide size ranging from a few millimetres to 75 cm in diameter. Exceptionally large size of the discs in these rocks represent the largest reported so far from any Ediacaran assemblage. Although, larger medu-soid discs have been reported from USA, they are from the middle Cambrian and even younger rocks. Presence of microbial mats and weed-like structures with well preserved hold fasts and horizontal rhizome-like structures in association with some of these large-sized discs support their animal affinity, which probably feed on this weed-like vegetations. This association also supports their benthic habitat. Unlike the general trend of sudden increase in size of organisms in Ediacaran period and further decrease in size during Cambrian, these discs continued increasing in size in Cambrian also.展开更多
Objective: To assess the validity, responsiveness, and test-retest reliability of DISCs (Depression Intensity Scale Circles) as a simple screening tool for depression in patients with cognitive or communicative defici...Objective: To assess the validity, responsiveness, and test-retest reliability of DISCs (Depression Intensity Scale Circles) as a simple screening tool for depression in patients with cognitive or communicative deficits following acquired brain injury. Design: Cohort analysis of consecutive patients entered into an integrated care pathway for screening and management of depression in the context of rehabilitation. Setting: Regional neurological rehabilitation service in the UK. Participants: 114 patients with complex disabilities caused by acquired brain injury (mean (SD) age, 42.8 (14.5) years). Main outcome measures: DISCs (a graphic rating scale depicting six circles with increasing proportion of dark shading), Numbered Graphic Rating Scale (NGRS), Yale single question (“Do you often feel sad or depressed”), Beck Depression Inventory-II (BDI-II), DSM-IV criteria for depression. Results: At initial assessment the DISCs correlated with total BDI-II scores (Spearman ρ= 0.66, P < 0.001), NGRS (ρ= 0.87, P < 0.001), and DSM-IV (ρ= 0.59, P < 0.001).A DISCs score≥2 identified depression (major or minor) according to DSM-IV criteria with 60%sensitivity, 87%specificity, 75%positive predictive value, and 77%negative predictive value. Test-retest reliability after 24 hours (n = 66) showed“excellent”.level of agreement (weighted κ= 0.84). In 45 patients who received intervention for depression, the DISCs showed a significant change in response to treatment (Wilcoxon; P < 0.001). Conclusions: DISCs had acceptable convergent validity, reliability, and responsiveness as a simple graded tool for screening and assessment of depression in patients with complex disabilities following acquired brain injury. It warrants further investigation in patients with more profound language and cognitive deficits for which it is primarily intended.展开更多
基金supported by the National Natural Science Foundation of China Nos.82370983,81671015(X.W.),82230030(Y.L.),82101043(S.C.)and 82370922(Y.F.)Beijing International Science and Technology Cooperation Project No.Z221100002722003(Y.L.)+4 种基金Beijing Natural Science Foundation Nos.L234017,JL23002(Y.L.),No.7242282(S.C.)and 7232217(Y.G.)Clinical Medicine Plus X-Young Scholars Project of Peking University No.PKU2024LCXQ039(Y.L.)National Program for Multidisciplinary Cooperative Treatment on Major Diseases No.PKUSSNMP-202013(X.W.)Hygiene and Health Development Scientific Research Fostering Plan of Haidian District Beijing No.HP2023-12-509001(J.Z.)Young Clinical Research Fund of the Chinese Stomatological Association No.CSA-02022-03(J.Z.).
文摘Temporomandibular joint(TMJ)disc displacement is one of the most significant subtypes of temporomandibular joint disorders,but its etiology and mechanism are poorly understood.In this study,we elucidated the mechanisms by which destruction of inflamed collagen fibrils induces alterations in the mechanical properties and positioning of the TMJ disc.By constructing a rat model of TMJ arthritis,we observed anteriorly dislocated TMJ discs with aggravated deformity in vivo from five weeks to six months after a local injection of Freund’s complete adjuvant.By mimicking inflammatory conditions with interleukin-1 beta in vitro,we observed enhanced expression of collagen-synthesis markers in primary TMJ disc cells cultured in a conventional two-dimensional environment.In contrast,three-dimensional(3D)-cultivated disc cell sheets demonstrated the disordered assembly of inflamed collagen fibrils,inappropriate arrangement,and decreased Young’s modulus.Mechanistically,inflammation-related activation of the nuclear factor kappa-B(NF-κB)pathway occurs during the progression of TMJ arthritis.NF-κB inhibition reduced the collagen fibril destruction in the inflamed disc cell sheets in vitro,and early NF-κB blockade alleviated collagen degeneration and dislocation of the TMJ discs in vivo.Therefore,the NF-κB pathway participates in the collagen remodeling in inflamed TMJ discs,offering a potential therapeutic target for disc displacement.
文摘目的:探讨Discs大同源物相关蛋白5(Discs large homolog associated protein 5,DLGAP5)在肝细胞癌(hepatocellular carcinoma,HCC)中的表达及其临床意义。方法:采用免疫组化法检测144对肝细胞癌组织和对应的癌旁组织样本中DLGAP5蛋白的表达,分析其表达与患者临床病理特征的关系,绘制Kaplan-Meier生存曲线分析DLGAP5表达对患者预后的影响。结果:肝细胞癌组织中DLGAP5表达阳性率77.8%,高于癌旁组织的阳性率38.9%,差异有统计学意义(P<0.01)。DLGAP5表达与肿瘤直径、TNM分级、脉管癌栓及肿瘤包膜完整性有关(均P<0.05),而与患者性别、年龄、乙型肝炎表面抗原、肝硬化及远处转移无关(均P>0.05)。Kaplan-Meier生存曲线分析显示,DLGAP5高表达组患者总生存率显著低于DLGAP5低表达组患者,差异具有统计学意义(P<0.05)。结论:DLGAP5蛋白在肝细胞癌中表达增高,其高表达与患者的预后不良有关。
基金National Natural Science Foundation of China(Grant No.81273777,81102606,81072831)the National Basic Re search Program of China(Grant No.2010CB530400)the Program for Changjiang Scholars and Innovative Research Team in University(PCSIRT,IRT1270)
文摘The inflammatory cytokine interleukin-1 beta （IL-1β） plays a key role in the process of intervertebral disc degenera- tion （IVDD）. In the present study, we aimed to evaluate the effect of pharmaco-serum of ＂Taoren-Honghua-herb pair＂ on IL-1β- induced chondrocyte degeneration in vitro. Taoren （Semen persicae） and Honghua （Safflower carthamus） were administered to the rats, and the pharmaco-serum was collected and prepared. Chondrocytes of the third passage, isolated from the rat＇s vertebral endplates, were treated by standard medium only （Group NC）, IL-1β （Group IL） or combination of IL-1β and pharmaco-serum （Group TRHH）. Cell proliferation and apoptosis were determined, and the expression of aggrecan, Col2ul, Coll0ul, IL-6 and SOX9 at the mRNA level in chondrocytes was quantified by real-time PCR. Immunohistochemistry staining of type II and X collagen and Safranine O staining were also used to evaluate the chondrocytes. Compared with the Group NC, IL-1β treatment inhibited the cell proliferation and induced the cell apoptosis （P〈0.05）, and the expression of aggrecan, Col2αl and SOX9 at the mRNA level was down-regulated. In contrast, the expression of Coll0ul and IL-6 was up-regulated after IL-1β treatment （P〈0.05）. Meanwhile, the immune-staining of type II collagen and Safranine O staining were decreased, while the staining of type X collagen was increased. Compared with the Group IL, cell proliferation was increased, and apoptosis of chondrocytes was decreased when cells were treated with the pharmaco-semm of TRHH-herb pair （P〈0.05）. The expression of aggrecan, Col2cd and SOX9 at the mRNA level was up-regulated, while that of Coll0cd and IL-6 was down-regulated （P〈0.05）. Saffanine O staining also showed increased positive staining （P〈0.05）. Taken together, the treatment of pharmaco-serum of TRHH-herb pair could prevent endplate chondrocyte degeneration induced by IL-1β.
文摘The noncarbonaceous Ediacaran discs of variable morphologies from the Jodhpur Sandstone Formation of the Marwar Supergroup, western Rajasthan, suggest different biologic affinities of plant and animal kingdom. These discs are commonly preserved on the bedding surfaces of siliciclastic sandstone and shale in strong positive relief and appear to possess a flexible to rigid body. Discs assignable to Aspidella, Cyclomedusa, Nimbia and Heimalora;all possibly inclining towards cnidarian affinity are being reported from the sandstone beds in Sursagar area. Variable morphologies among discs preserved in siliciclastic shale beds from the Artiya Kalan area support scyphozoan affinity (earlier named Marsonia from the same locality) and cnidarian affinity for small discs comparable with Funisia (considered being the first animals having sexual reproduction). Disc’s morphologies also suggest ephyra stage of Aurilia (a cnidarian form) or budding stages of some fungi, like Germinosphaera (multicellular benthic fungal fossils) and noncarbonaceous discs with well preserved wrinkles and folds like in Chuaria. Discs from the Jodhpur Sandstone, may at times display taphonomic interplay, but consistency and repetition in morphology support variable biological affinities representing diverse assemblage and advance ecosystem prevailing during Ediacaran period. A degree of genetic variability can be expected within any taxa, and this may be compounded by preservation factors affecting the Jodhpur Ediacaran discs. Sudden increase in size or gigantism is a common feature of Ediacaran life, which is evident in case of Jodhpur discs also. On the basis of fossil assemblage, the Jodhpur Group (the Marwar Supergroup) is regionally correlated with the Bhander Group of the Vindhyan Supergroup and Krol Group of Lesser Himalaya. Globally, the assemblage is comparable with the Long Mynd Group, Shropshire, UK, Fermuse Formation Newfoundland, South Australia, Russia and Norway.
文摘The present research is focused on the numerical crack coalescence analysis of the micro-cracks and cracks produced during the cutting action of TBM disc cutters. The linear elastic fracture mechanics(LEFM) concepts and the maximum tangential stress criterion are used to investigate the micro crack propagation and its direction underneath the excavating discs. A higher order displacement discontinuity method with quadratic displacement discontinuity elements is used to estimate the stress intensity factors near the crack tips. Rock cutting mechanisms under single and double type discs are simulated by the proposed numerical method.The main purposes of the present modeling are to simulate the chip formation process of indented rocks by single and double discs.The effects of specific disc parameters(except speed) on the thrust force Ft, the rolling force Fr, and the specific energy ES are investigated. It has been shown that the specific energy(energy required to cut through a unit volume of rock) of the double disc is less than that of the single disc. Crack propagation in rocks under disc cutters is numerically modeled and the optimum ratio of disc spacing S to penetration depth Pd(i.e. S/Pd ratio) of about 10 is obtained, which is in good agreement with the theoretical and experimental results cited in the literature.
文摘An internal failure mode for a soil-nailed system consists of failure at nail heads,slope facing,nail strength,along groutesoil interface and pullout failure.A better understanding of pullout of soil nail thus becomes important to assess the stability of a soil-nailed system.In the present study,an investigation into the pullout behaviour of soil nail with circular discs along the shaft has been carried out by a threedimensional finite element analysis using Abaqus/Explicit routine.A total of 67 simulations have been performed to accurately predict the pullout behaviour of soil nail.The soil nail under study has circular discs along its shaft varying in numbers from 1 to 4.The pullout of this soil nail in a pullout test box has been simulated with a constant overburden pressure of 20 kPa acting on the nail.The pullout load edisplacement characteristics,stresses around soil nail and failure mechanism during pullout are studied.Variations of dimensionless factors such as normalised pullout load factor and bearing capacity factor have been obtained with different combinations of parameters in terms of relative disc spacing ratio,anchorage length ratio,embedment ratio,diameter ratio and displacement ratio.From the results of analyses,it is found that nail with more circular discs requires higher pullout load.There are critical relative disc spacing ratio and diameter ratio which significantly affect the pullout behaviour of nail.
基金supported by the National Natural Science Foundation of China(Grant Nos.11504199,11703015 and U1831207)the China Postdoctoral Science Foundation(Grant No.2017M612233)+1 种基金the Natural Science Foundation of Shandong Province(Grant Nos.ZR2015AM004 and ZR2017BA006)Technology Program of Qufu Normal University(xkj201614)
文摘A 200-second X-ray quasi-periodicity in the 2-8 ke V band from Swift J1644+57 was found by Reis et al.From the onset time of quasi-periodic oscillation(QPO),we show that Swift J1644+57 is a plunging event.This QPO may be related to discrete clumps from the accretion disk falling into a supermassive black hole,then the outflow in the jet may be also discontinuous.We estimate the lifetime of clumps to be about several hundreds seconds and the fraction of clumpy ejecta to be about 30% from the QPO.The other possible model involves the interface between the inflow and jet magnetosphere in the magnetically choked accretion flow.Theory and numerical simulations indicate that a magnetic Rayleigh-Taylor and Kelvin-Helmholtz unstable magnetospheric interface can produce a jet-disk QPO mechanism.This event may be the first evidence of jet-disk QPO.From observations,the two models are comparable.
基金Supported by the National Natural Science Foundation of China under Grant No 60577035.
文摘When the techniques of integrating the variation of the conventional DVD,the high-density multilevel run-length pit depth and width simultaneously are adopted to limited read-only optical storage method is achieved. The dynamic range of readout signal is greatly enlarged in comparison with keeping one parameter varied, and the recording levels number can be obviously increased. The discs can be manufactured using standard photoresist mastering and replication techniques with great compatibility to conventional binary read-only discs. Experimental results show that eight-level read-only optical disc can be realized and the capacity can be increased to 20 GB.
基金supported by the Asher Fund for Space Research at the Technionthe E. and J. Bishop Research Fund at the Technion
文摘We propose that sub-Keplerian accretion belts around stars might launch jets. The sub-Keplerian inflow does not form a rotationally supported accretion disk, but it rather reaches the accreting object from a wide solid angle. The basic ingredients of the flow are a turbulent region where the accretion belt interacts with the accreting object via a shear layer, and two avoidance regions on the poles where the accretion rate is very low. A dynamo that is developed in the shear layer amplifies magnetic fields to high values. It is likely that the amplified magnetic fields form polar outflows from the avoidance regions. Our speculative belt-launched jets model has implications on a rich variety of astrophysical objects, from the removal of common envelopes to the explosion of core collapse supernovae by jittering jets.
基金Financial assistance from DST, New Delhi in form of a WOS-A project No. SR/OY/WOS-A/ES-20/ 2008
文摘Ediacaran discs from the Jodhpur Sandstone of the Marwar Supergroup, Rajasthan, exhibit a wide size ranging from a few millimetres to 75 cm in diameter. Exceptionally large size of the discs in these rocks represent the largest reported so far from any Ediacaran assemblage. Although, larger medu-soid discs have been reported from USA, they are from the middle Cambrian and even younger rocks. Presence of microbial mats and weed-like structures with well preserved hold fasts and horizontal rhizome-like structures in association with some of these large-sized discs support their animal affinity, which probably feed on this weed-like vegetations. This association also supports their benthic habitat. Unlike the general trend of sudden increase in size of organisms in Ediacaran period and further decrease in size during Cambrian, these discs continued increasing in size in Cambrian also.
文摘Objective: To assess the validity, responsiveness, and test-retest reliability of DISCs (Depression Intensity Scale Circles) as a simple screening tool for depression in patients with cognitive or communicative deficits following acquired brain injury. Design: Cohort analysis of consecutive patients entered into an integrated care pathway for screening and management of depression in the context of rehabilitation. Setting: Regional neurological rehabilitation service in the UK. Participants: 114 patients with complex disabilities caused by acquired brain injury (mean (SD) age, 42.8 (14.5) years). Main outcome measures: DISCs (a graphic rating scale depicting six circles with increasing proportion of dark shading), Numbered Graphic Rating Scale (NGRS), Yale single question (“Do you often feel sad or depressed”), Beck Depression Inventory-II (BDI-II), DSM-IV criteria for depression. Results: At initial assessment the DISCs correlated with total BDI-II scores (Spearman ρ= 0.66, P < 0.001), NGRS (ρ= 0.87, P < 0.001), and DSM-IV (ρ= 0.59, P < 0.001).A DISCs score≥2 identified depression (major or minor) according to DSM-IV criteria with 60%sensitivity, 87%specificity, 75%positive predictive value, and 77%negative predictive value. Test-retest reliability after 24 hours (n = 66) showed“excellent”.level of agreement (weighted κ= 0.84). In 45 patients who received intervention for depression, the DISCs showed a significant change in response to treatment (Wilcoxon; P < 0.001). Conclusions: DISCs had acceptable convergent validity, reliability, and responsiveness as a simple graded tool for screening and assessment of depression in patients with complex disabilities following acquired brain injury. It warrants further investigation in patients with more profound language and cognitive deficits for which it is primarily intended.
