Interface bond degradation and damage characteristics of full-length grouted rock bolt in tunnels with high temperature

Full-length grouted bolts play a crucial role in geotechnical engineering thanks to their excellent stability.However,few studies have been concerned with the degrading performance of grouted rock bolts caused by extensive and continuous heat conduction from surrounding rocks in high-geothermal tunnels buried more than 100 m(temperature from 28C to 100C).To investigate the damage mechanism,we examined the time-varying behaviors of grouted rock bolts in both constant and variable temperature curing environments and their damage due to the coupling effects of high temperature and humidity through mechanical and micro-feature tests,including uniaxial compression test,pull-out test,computed tomography(CT)scans,X-ray diffraction(XRD)test,thermogravimetric analysis(TGA),etc.,and further analyzed the relationship between grout properties and anchorage capability.In order to facilitate a rapid assessment and control of the anchorage performance of anchors in different conditions,results of the interface bond degradation tests were correlated to environment parameters based on the damage model of interfacial bond stress proposed.Accordingly,a thermal hazard classification criterion for anchorage design in high-geothermal tunnels was suggested.Based on the reported results,although high temperature accelerated the early-stage hydration reaction of grouting materials,it affected the distribution and quantity of hydration products by inhibiting hydration degree,thus causing mechanical damage to the anchorage system.There was a significant positive correlation between the strength of the grouting material and the anchoring force.Influenced by the changes in grout properties,three failure patterns of rock bolts typically existed.Applying a hot-wet curing regime results in less reduction in anchorage force compared to the hot-dry curing conditions.The findings of this study would contribute to the design and investigations of grouted rock bolts in high-geothermal tunnels.

Energy model based sensorless estimation method for operational temperature of braking resistor onboard metro vehicles

Purpose–This study aims to improve the availability of regenerative braking for urban metro vehicles by introducing a sensorless operational temperature estimation method for the braking resistor(BR)onboard the vehicle,which overcomes the vulnerability of having conventional temperature sensor.Design/methodology/approach–In this study,the energy model based sensorless estimation method is developed.By analyzing the structure and the convection dissipation process of the BR onboard the vehicle,the energy-based operational temperature model of the BR and its cooling domain is established.By adopting Newton’s law of cooling and the law of conservation of energy,the energy and temperature dynamic of the BR can be stated.To minimize the use of all kinds of sensors(including both thermal and electrical),a novel regenerative braking power calculation method is proposed,which involves only the voltage of DC traction network and the duty cycle of the chopping circuit;both of them are available for the traction control unit(TCU)of the vehicle.By utilizing a real-time iterative calculation and updating the parameter of the energy model,the operational temperature of the BR can be obtained and monitored in a sensorless manner.Findings–In this study,a sensorless estimation/monitoring method of the operational temperature of BR is proposed.The results show that it is possible to utilize the existing electrical sensors that is mandatory for the traction unit’s operation to estimate the operational temperature of BR,instead of adding dedicated thermal sensors.The results also validate the effectiveness of the proposal is acceptable for the engineering practical.Originality/value–The proposal of this study provides novel concepts for the sensorless operational temperature monitoring of BR onboard rolling stocks.The proposed method only involves quasi-global electrical variable and the internal control signal within the TCU.

Comparison of Two Novel MRAS Based Strategies for Identifying Parameters in Permanent Magnet Synchronous Motors

Two model reference adaptive system （MRAS） estimators are developed for identifying the parameters of permanent magnet synchronous motors （PMSM） based on the Lyapunov stability theorem and the Popov stability criterion, respectively. The proposed estimators only need online measurement of currents, voltages, and rotor speed to effectively estimate stator resistance, inductance, and rotor flux-linkage simultaneously. The performance of the estimators is compared and verified through simulations and experiments, which show that the two estimators are simple, have good robustness against parameter variation, and are accurate in parameter tracking. However, the estimator based on the Popov stability criterion, which can overcome parameter variation in a practical system, is superior in terms of response speed and convergence speed since there are both proportional and integral units in the estimator, in contrast to only one integral unit in the estimator based on the Lyapunov stability theorem. In addition, the estimator based on the Popov stability criterion does not need the expertise that is required in designing a Lyapunov function.

Robust Position Anti-Interference Control for PMSM Servo System With Uncertain Disturbance

Aiming to suppress the influence of uncertain disturbances in the drive control of permanent magnet synchronous machines(PMSM),such as the parameter uncertainties and load disturbance,a robust anti-interference control for the angular position tracking control of a PMSM servo system has been proposed in this paper.During the position tracking,uncertain system disturbances being regarded as a lumped unknown term will be online observed by a nonlinear disturbance observer(NDOB),of which the influence will consequently be counteracted by a robust backstepping compensator(RBC).The asymptotical stability of proposed control scheme is analyzed and designed according to the Lyapunov stability criterion,and its convergence against the system uncertain disturbance is verified on a prototype PMSM servo platform and shows good performance in rotor angular position tracking and anti-interference.

Synthetic and immunological studies on the OCT4 immunodominant motif antigen-based anti-cancer vaccine

Objective:Cancer stem cell is one of the important causes of tumorigenesis as well as a drug target in the treatment of malignant tumor.However,at present,there is no immune vaccine targeting these cells.Octamer-binding transcription factor 4(OCT4),a marker of embryonic stem cells and germ cells,often highly expresses in the early stages of tumorigenesis and is therefore a good candidate for cancer vaccine development.Methods:To identify the optimal carrier and adjuvant combination,we chemically synthesized and linked three different OCT4 epitope antigens to a carrier protein,keyhole limpet hemocyanin(KLH),combined with Toll-like receptor 9 agonist(TLR9).Results:Immunization with OCT4-3+TLR9 produced the strongest immune response in mice.In prevention assays,significant tumor growth inhibition was achieved in BABL/c mice treated with OCT4-3+TLR9(P<0.01).Importantly,the results showed that cytotoxic T lymphocyte activity and the inhibition of tumor growth were enhanced in mice immunized with OCT4-3 combined with TLR9.Meanwhile,multiple cytokines[such as interferon(IFN)-γ(P<0.05),interleukin(IL)-12(P<0.05),IL-2(P<0.01),and IL-6(P<0.05)]promoting cellular immune responses were shown to be greatly enhanced in mice immunized with OCT4-3+TLR9.Moreover,we considered safety considerations in terms of the composition of the vaccines to help facilitate the development of effective next-generation vaccines.Conclusions:Collectively,these experiments demonstrated that combination therapy with TLR9 agonist induced a tumor-specific adaptive immune response,leading to the suppression of primary tumor growth in testis embryonic carcinoma.

New Approach to Stability Analysis and Stabilization of Discrete-Time T-S Fuzzy Descriptor Systems

The problems of stability and state feedback control for a class of discrete-time T-S fuzzy descriptor systems are investigated in this paper. Based on fuzzy Lyapunov function,a set of slack variables is introduced to remove the basic semi-definite matrix inequality condition to check the regularity,causality and stability of discrete-time T-S fuzzy descriptor systems; a new sufficient condition for the discrete-time T-S fuzzy descriptor systems to be admissible is proposed in terms of strict linear matrix inequalities( LMIs). And a sufficient condition is proposed for the existence of state feedback controller in terms of a set of coupled strict LMIs.Finally,an illustrative example is presented to demonstrate the effectiveness of the proposed approach.

Message from Editors

Due to high torque density and efficiency,permanent magnet machines have been used for many applications,ranging from domestic appliance,industrial automation,robot,electric vehicle,to wind power generation etc.Various novel permanent magnet machine topologies have been developed and many new topologies are still emerging,whilst many novel control strategies are being developed.On the other hand,magnetless machines,including induction,switched and synchronous reluctance,and wound-field synchronous machines,can eliminate the use of expensive rare-earth magnets and their design,analysis and control are currently under extensive investigation.

Serum activin A as a prognostic biomarker for community acquired pneumonia

BACKGROUND It is essential to develop new biomarker with effective prognostic roles because of the unclear clinical use of the current community-acquired pneumonia(CAP)predictors.AIM To evaluate the association between serum activin A levels and prognosis in CAP patients.METHODS A total of 168 CAP individuals grouped according to the severity and prognosis of illness condition,and 48 healthy individuals as the control group were enrolled in this study.Circulating concentrations of activin A were measured using enzymelinked immunoassays.The interaction between activin A levels and etiologies of CAP was determined.Based on the severity of CAP,110 patients(65.48%)were categorized into group-I,42(25%)cases were grouped into group-II,and 16(9.52%)cases were categorized into group-III.RESULTS Serum activin A levels were higher in patients with CAP than controls,but independent of etiology.Moreover,the scores of Pneumonia Severity Index(PSI)and CURB-65 positively correlated with the increasing levels of serum activin A,and were at their highest peak in individuals in group-III(P<0.001).Combining activin A with CURB-65 or PSI was more effective in improving predictive property(P<0.01).According to Cox proportional regression analysis,after adjusting clinical parameters,we confirmed that activin A showed a powerful predictive property for hospital mortality in CAP patients(P<0.001).CONCLUSION Higher level of serum activin A was associated with poor prognosis of CAP.Activin A can be used as a more valuable biomarker of prognosis in CAP patients.

四川诺水河珍稀水生动物国家级自然保护区鱼类资源现状

四川诺水河珍稀水生动物国家级自然保护区由嘉陵江支流渠江上游的大通江及支流小通江组成,为全面了解该保护区的鱼类资源现状,作者于2015年11月至2017年1月对30个采样点进行了5次资源调查。结果显示,保护区共分布鱼类57种,隶属4目13科45属,其中调查采集47种,访问调查获得10种。国家二级重点保护鱼类有1种,即岩原鲤(Procypris rabaudi),长江上游特有鱼类有12种,列入《中国脊椎动物红色名录》的易危鱼类3种。保护区以小型鱼类为主,优势种为宽鳍鱲(Zacco platypus)、嘉陵颌须鮈(Gnarhopogon herzensteini)和切尾拟鲿(Pseudobagrus truncatus)。保护区鱼类多样性较高,ShannonWiener多样性指数、Margalef物种丰富度指数、Simpson优势度指数和Pielou均匀度指数分别为2.900、5.198、0.931、0.753。Jaccard相似性系数表明,大通江和小通江鱼类群落相似度较高,同一河流不同河段间的相似度整体上与河段间距离成反比;而不同河流相似海拔高度河段间鱼类群落相似度更高。保护区鱼类资源的衰退主要由过度捕捞、栖息地破坏以及水体污染等人类活动所致。

Excessive gestational weight gain in early pregnancy and insufficient gestational weight gain in middle pregnancy increased risk of gestational diabetes mellitus

Background:Gestational weight gain(GWG)is associated with the risk of gestational diabetes mellitus(GDM).However,the effect of weight gain in different trimesters on the risk of GDM is unclear.This study aimed to evaluate the effect of GWG on GDM during different trimesters.Methods:A birth cohort study was conducted from 2017 to 2020 in Shenzhen,China.In total,51,205 participants were included comprising two models(early pregnancy model and middle pregnancy model).Gestational weight(kg)was measured at each prenatal clinical visit using a standardized weight scale.Logistic regression analysis was used to assess the risk of GDM.Interaction analysis and mediation effect analysis were performed in the middle pregnancy model.Results:In the early pregnancy model,the risk of GDM was 0.858 times lower(95%confidence interval[CI]:0.786,0.937)with insufficient GWG(iGWG)and 1.201 times higher(95%CI:1.097,1.316)with excessive GWG after adjustment.In the middle pregnancy model,the risk of GDM associated with iGWG increased 1.595 times(95%CI:1.418,1.794)after adjustment;for excessive GWG,no significant difference was found(P=0.223).Interaction analysis showed no interaction between GWG in early pregnancy(GWG-E)and GWG in middle pregnancy(GWG-M)(F=1.268;P=0.280).The mediation effect analysis indicated that GWG-M plays a partial mediating role,with an effect proportion of 14.9%.Conclusions:eGWG-E and iGWG-M are associated with an increased risk of GDM.Strict control of weight gain in early pregnancy is needed,and sufficient nutrition should be provided in middle pregnancy.

BIGpre: A Quality Assessment Package for Next-Generation Sequencing Data

The emergence of next-generation sequencing （NGS） technologies has significantly improved sequencing throughput and reduced costs. However, the short read length, duplicate reads and massive volume of data make the data processing much more difficult and complicated than the first-generation sequencing technology. Al- though there are some software packages developed to assess the data quality, those packages either are not easily available to users or require bioinformatics skills and computer resources. Moreover, almost all the quality assessment software currently available didn＇t taken into account the sequencing errors when dealing with the du- plicate assessment in NGS data. Here, we present a new user-friendly quality assessment software package called BIGpre, which works for both Illumina and 454 platforms. BIGpre contains all the functions of other quality assessment software, such as the correlation between forward and reverse reads, read GC-content distribution, and base Ns quality. More importantly, BIGpre incorporates associated programs to detect and remove duplicate reads after taking sequencing errors into account and trimming low quality reads from raw data as well. BIGpre is primarily written in Perl and integrates graphical capability from the statistics package R. This package produces both tabular and graphical summaries of data quality for sequencing datasets from Illumina and 454 platforms. Processing hundreds of millions reads within minutes, this package provides immediate diagnostic information for user to manipulate sequencing data for downstream analyses. BIGpre is freely available at http：//bigpre.sourceforge.net/.

Discovery,Identification and Comparative Analysis of Non-Specific Lipid Transfer Protein (nsLtp) Family in Solanaceae

Plant non-specific lipid transfer proteins （nsLtps） have been reported to be involved in plant defense activity against bacterial and fungal pathogens. In this study, we identified 135 （122 putative and 13 previously identified） Solanaceae nsLtps, which are clustered into 8 different groups. By comparing with Boutrot’s nsLtp classification, we classified these eight groups into five types （I, II, IV, IX and X）. We compared Solanaceae nsLtps with Arabidopsis and Gramineae nsLtps and found that （1） Types I, II and IV are shared by Solanaceae, Gramineae and Arabidopsis; （2） Types III, V, VI and VIII are shared by Gramineae and Arabidopsis but not detected in Solanaceae so far; （3） Type VII is only found in Gramineae whereas type IX is present only in Arabidopsis and Solanaceae; （4） Type X is a new type that accounts for 52.59% Solanaceae nsLtps in our data, and has not been reported in any other plant so far. We further built and compared the three-dimensional structures of the eight groups, and found that the major functional diversification within the nsLtp family could be predated to the monocot/dicot divergence, and many gene duplications and sequence variations had happened in the nsLtp family after the monocot/dicot divergence, especially in Solanaceae.

The role of intraoperative electron radiotherapy in centrally located hepatocellular carcinomas treated with narrow-margin (<1 cm) hepatectomy: a prospective, phase 2 study

Background: Postoperative radiotherapy (RT) is known to play an important role in the treatment of hepatocellular carcinomas (HCCs), but the specific role of intraoperative electron radiotherapy (IOERT) in HCCs remains unclear. The aim of this study was to investigate the safety and efficacy of IOERT in centrally located HCCs treated with narrow-margin (<1 cm) hepatectomy. Methods: This was a single-center, phase 2, prospective non-randomized controlled study, including 268 patients with centrally located HCCs who underwent narrow-margin hepatectomy. The patients were subsequently allocated to the IOERT group (n=59) or to the control group (n=65). The primary outcome of the study was to compare recurrence-free survival (RFS) between the IOERT group and the control group, and the secondary outcome was to compare overall survival (OS) rate between the two groups. Results: Of 268 patients enrolled, a total of 124 were included in the study: 59 in IOERT group, 65 in control group. The 1-, 2-, 3-year RFS rates were 79.3%, 62.1% and 45.8% for patients in the IOERT group, and 47.6%, 28.6%, and 22.9% for patients in the control group, respectively (P=0.025). The 1-, 2-, and 3-year OS rates were 100.0%, 94.9%, and 83.7% for patients in the IOERT group, and 92.3%, 87.5%, and 79.4% for patients in the control group, respectively (P=0.314). Subgroup analysis of MVI (+) patients revealed that RFS and OS are significantly prolonged in the IOERT subgroup as compared to the control, whereas there was no significant difference of RFS and OS between the two groups in MVI (−) patients. Conclusions: IOERT for centrally located HCCs with concurrent narrow-margin hepatectomy was feasible and safe. Statistically better RFS rate was observed in the IOERT group compared to the control group. Subgroup analysis revealed that IOERT was more beneficial for postoperative survival of HCC patients with MVI. Trial Registration: ChiCTR-TRC-12002802;www.who.int/ictrp.

Transcriptomic study of the red palm weevil Rhynchophorus ferrugineus embryogenesis

The red palm weevil （RPW）, Rhynchophorus ferrugineus （Coleoptera： Cur- culionidae）, is an invasive, concealed and destructive tissue borer, and it becomes a lethal pest of the palm family of plants and has been reported to attack 20 palm species around the globe. Here we report a systematic transcriptomic study on embryogenesis of RPW, where we analyze the transcriptomes across five developmental stages of RPW embryogenesis, involving four embryonic stages （El, E2, E3 and E4） and one larval stage （L1）. Using the RNA-seq and next-generation platforms, we generated 80 to 91 million reads for each library and assemble 22 532 genes that are expressed at different embryonic stages. Among the total transcripts from the five embryonic development stages, we found that 30.45 % are differentially expressed, 10.10 % show stage-specificity and even a larger fraction, 62.88 %, exhibit constitutive expression in all the stages. We also analyzes the expression dynamics of several conserved signaling pathways （such as Hedgehog, JAK-STAT, Notch, TGF-β, Ras/MAPK and Writ）, as well as key developmental genes, including those related to apoptosis, axis formation, Hox complex, neurogenesis and segmentation. The datasets provide an essential resource for gene annotation and RPW functional genomics, including studies by using tools and concepts from multiple disciplines, such as development, physiology, biochemistry, molecular biology and genetics.