Bionic lightweight design of limb leg units for hydraulic quadruped robots by additive manufacturing and topology optimization

Galloping cheetahs,climbing mountain goats,and load hauling horses all show desirable locomotion capability,which motivates the development of quadruped robots.Among various quadruped robots,hydraulically driven quadruped robots show great potential in unstructured environments due to their discrete landing positions and large payloads.As the most critical movement unit of a quadruped robot,the limb leg unit(LLU)directly affects movement speed and reliability,and requires a compact and lightweight design.Inspired by the dexterous skeleton–muscle systems of cheetahs and humans,this paper proposes a highly integrated bionic actuator system for a better dynamic performance of an LLU.We propose that a cylinder barrel with multiple element interfaces and internal smooth channels is realized using metal additive manufacturing,and hybrid lattice structures are introduced into the lightweight design of the piston rod.In addition,additive manufacturing and topology optimization are incorporated to reduce the redundant material of the structural parts of the LLU.The mechanical properties of the actuator system are verified by numerical simulation and experiments,and the power density of the actuators is far greater than that of cheetah muscle.The mass of the optimized LLU is reduced by 24.5%,and the optimized LLU shows better response time performance when given a step signal,and presents a good trajectory tracking ability with the increase in motion frequency.

Buxu Tongyu Granule Alleviates Myocardial Ischemia by Activating Vascular Smooth Muscle Cell Soluble Guanylate Cyclase to Inhibit Abnormal Vasomotion

Myocardial ischemia is a serious threat to human health,and vascular dysfunction is its main cause.Buxu Tongyu(BXTY)Granule is an effective traditional Chinese medicine(TCM)for treating myocardial ischemia.However,the underlying mechanism of BXTY is still unclear.In this study,we demonstrate that BXTY ameliorates myocardial ischemia by activating the soluble guanylate cyclase(sGC)-30,50-cyclic guanosine monophosphate(cGMP)-protein kinase G(PKG)signaling pathway in vascular smooth muscle cells(VSMCs)to dilate the arteries.BXTY was given by gavage for ten consecutive days before establishing an animal model of acute myocardial ischemia in mice via the intraperitoneal injection of pituitrin.The results showed that BXTY alleviated the symptoms of myocardial ischemia induced by pituitrin in mice,including electrocardiogram abnormalities and changes in plasma enzymes.In addition,BXTY dilated pre-constricted blood vessels and inhibited the vasoconstriction of the superior mesenteric artery in a dose-dependent but endothelial-independent manner.These effects were eliminated by preincubating vascular rings with the sGC inhibitors NS 2028 or ODQ,or with the PKG inhibitor KT 5823.Moreover,BXTY increased the protein expression of sGC-b1 and the intracellular second messenger cGMP level in mouse aortic vascular smooth muscle cells(MOVAs).NS 2028 or ODQ reversed these effects of BXTY.The expression level of the cGMP downstream effector protein PKG-1 increased after treating MOVAs with BXTY.NS 2028,ODQ,or KT 5823 also reversed this effect of BXTY.In conclusion,BXTY can improve the symptoms of acute myocardial ischemia in mice,and activating the sGC-cGMP-PKG pathway in VSMCs to induce vasodilation is its key pharmacodynamic mechanism.

Proposal of Equivalent Porosity Indicator for Foam Aluminum Based on GRNN

To gain a more comprehensive understanding and evaluate foam aluminum's performance,researchers have introduced various characterization indicators.However,the current understanding of the significance of these indicators in analyzing foam aluminum's performance is limited.This study employs the Generalized Regression Neural Network(GRNN)method to establish a model that links foam aluminum's microstructure characterization data with its mechanical properties.Through the GRNN model,researchers extracted four of the most crucial features and their corresponding weight values from the 13 pore characteristics of foam aluminum.Subsequently,a new characterization formula,called“Wang equivalent porosity”(WEP),was developed by using residual weights assigned to the feature weights,and four parameter coefficients were obtained.This formula aims to represent the relationship between foam aluminum's microstructural features and its mechanical performance.Furthermore,the researchers conducted model verification using compression data from 11 sets of foam aluminum.The validation results showed that among these 11 foam aluminum datasets,the Gibson-Ashby formula yielded anomalous results in two cases,whereas WEP exhibited exceptional stability without any anomalies.In comparison to the Gibson-Ashby formula,WEP demonstrated an 18.18%improvement in evaluation accuracy.

A Study of Myocardial Ischemia Model Induced by Left Coronary Artery Ligation in Rats

Objective: Coronary artery was ligated to study the characteristics of myocardial ischemia in rats. Methods: The left anterior descending artery was ligated to establish the rat model of acute myocardial ischemia. All animals were divided into normal control group, sham operation group and model group. 1, 2 and 4 weeks after modeling, ECG (II lead) was recorded, the weight of whole heart and left ventricle were recorded and organ indexes were calculated;myocardial infarct size was determined by TTC;CK, CK-MB, LDH, AST contents of serum were detected;cardiac function was determined by left ventricular intubation via carotid artery and left ventricular was taken to perform pathological observation. Results: 1 week after modeling, compared with the sham operation group, the ECG and heart function index of rats model had significant change, but the myocardial enzymes did not change significantly;4 weeks after modeling, the ECG and cardiac function of animal models had a recovery trend, but the myocardial enzymes, including CK, CK-MB, LDH, AST, were significantly increased;1 week after modeling, the left ventricular indexes of model rats were increased;the infarct size was about 30%, myocardial cell necrosis and granulation tissue hyperplasia could be observed in infarction area;with the modeling time extended, from 2 to 4 weeks, the left ventricular and heart indexes of model group were significantly increased;the infarct size was relatively constant, left ventricular became thickly, and fibrous or granulation tissue was significantly proliferated in infarction area under microscope. Conclusion: The indexes of myocardial ischemia induced by coronary artery ligation in rats are different at different time points. The results suggest that the time point should be selected to observe the anti-myocardial ischemia effect of the subjects from different aspects.

Isolation and Functional Characterization of a B3 Transcription Factor Gene <i>FUSCA3</i>Involved in Pre-Harvest Sprouting Resistance in Wheat

Pre-harvest sprouting (PHS) reduces yields and grain quality, resulting in seriously economic losses in wheat. It has been showed that PHS is significantly correlated to seed dormancy levels. FUSCA3 (FUS3) gene is considered to be the key regulator of seed dormancy. However, little information is available about the function of FUS3 gene (TaFUS3) in wheat. In this study, three homologous genes were identified in wheat grain, and their functions were investigated by gene silencing. Three full-length DNA (3477, 3534 and 3501 bp) and cDNA (1015, 1012 and 1015 bp) sequences encoding a B3 transcription factor, designated TaFUS3-3A, TaFUS3-3B and TaFUS3-3D, were first isolated from common wheat. The transcription of three TaFUS3 genes in seed development and germination process was detected. TaFUS3-3B and TaFUS3-3D had similar expression profiles, and high levels of gene transcripts were detected in seeds at 25 DAP (days after pollination) and after 24 h of imbibition. However, the transcription of TaFUS3-3A was not detected. Silencing of TaFUS3 in common wheat spikes resulted in increased seed germination and PHS. Compared with wild-type, the TaFUS3-silenced plants showed increased expression of genes related to GA biosynthesis and ABA metabolism, and decreased expression of genes associated with ABA biosynthesis. Moreover, silencing of TaFUS3 in wheat plants led to a decrease in embryo sensitivity to ABA and changed the expression of genes involved in ABA signal transduction. The results of gene silencing indicated that TaFUS3 plays a positive role in wheat seed dormancy and PHS-resistance, which might be associated with ABA, GA level and signal transduction.

Research on Smart Meteorology Serving Agriculture under the Rural Revitalization Strategy—Taking Mingshan Tea as an Example

It is imperative to prioritize the development of agriculture and rural areas and improve the efficiency of smart meteorological services for agricultural products under the strategy of rural revitalization. In this article, we take Mingshan tea, one of the characteristic industries in Sichuan Province, as an example to explore the related issues of smart meteorology serving agriculture. The status, value, and demand of tea smart meteorological services have been analyzed in this article. In addition, in response to the increasing demand for meteorological services in agricultural production, we have proposed to solve problem of tea meteorological service by strengthening talent, technology, product refinement, and dissemination. We have also proposed specific measures for tea intelligent meteorology to serve agriculture, in order to provide reference for future service practices. We need to continuously improve the methods and content of meteorological services, and improve the level of meteorological services. At the same time, utilizing smart meteorological service methods provides strong support for rural revitalization. This not only increases the income of tea farmers, but also maximizes the technical support role of meteorology in disaster prevention and reduction.

Serum IL-1β and IL-18 correlate with ESR and CRP in multidrug-resistant tuberculosis patients

Dear Editor： The emergence of multidrug-resistant tuberculosis （MDR-TB） is bringing new challenges. MDR-TB is caused by Mycobacterium tuberculosis （M. tuberculosis） that is resistant to isoniazid and rifampicin, with or with- out resistance to other anti-tuberculosis drugs. Approximately 450,000 people developed MDR-TB worldwide in 2012 and an estimated 170,000 people died from the disease. Bacterial burden is not strictly corre- lated with disease progression, and several hallmarks of severe tuberculosis suggest that insufficiently controlled inflammation plays an important role in pathogenesis.

Telomere-to-telomere and gap-free reference genome assembly of the kiwifruit Actinidia chinensis

Kiwifruit is an economically and nutritionally important fruit crop with extremely high contents of vitamin C.However,the previously released versions of kiwifruit genomes all have a mass of unanchored or missing regions.Here,we report a highly continuous and completely gap-free reference genome of Actinidia chinensis cv.‘Hongyang’,named Hongyang v4.0,which is the first to achieve two de novo haploid-resolved haplotypes,HY4P and HY4A.HY4P and HY4A have a total length of 606.1 and 599.6 Mb,respectively,with almost the entire telomeres and centromeres assembled in each haplotype.In comparison with Hongyang v3.0,the integrity and contiguity of Hongyang v4.0 is markedly improved by filling all unclosed gaps and correcting some misoriented regions,resulting in∼38.6–39.5 Mb extra sequences,which might affect 4263 and 4244 protein-coding genes in HY4P and HY4A,respectively.Furthermore,our gap-free genome assembly provides the first clue for inspecting the structure and function of centromeres.Globally,centromeric regions are characterized by higher-order repeats that mainly consist of a 153-bp conserved centromere-specific monomer(Ach-CEN153)with different copy numbers among chromosomes.Functional enrichment analysis of the genes located within centromeric regions demonstrates that chromosome centromeres may not only play physical roles for linking a pair of sister chromatids,but also have genetic features for participation in the regulation of cell division.The availability of the telomere-to-telomere and gap-free Hongyang v4.0 reference genome lays a solid foundation not only for illustrating genome structure and functional genomics studies but also for facilitating kiwifruit breeding and improvement.

Long-term follow-up of abdominal aortic balloon occlusion for the treatment of pernicious placenta previa with placenta accreta

Objective:To evaluate the efficacy and safety of balloon occlusion of the abdominal aorta for the treatment of pernicious placenta previa with placenta accreta.Methods:The clinical data of 623 patients with pernicious placenta previa combined with placenta accrete,who were admitted to our hospital from January 2013 to January 2019 were retrospectively analyzed.All patients underwent abdominal aortic balloon occlusion combined with cesarean section,and 78 patients underwent sequential bilateral uterine artery embolization.We analyzed the operation time,intraoperative blood loss,blood transfusion volume,intraoperative and postoperative complications,fetal radiation exposure time and dose,and the Apgar score of the newborns.We also performed other evaluations to ascertain the efficacy and safety of abdominal aortic balloon occlusion treatment for dangerous placenta previa with placenta accrete.Results:Of the 623 patients,545 underwent only abdominal aortic balloon occlusion,and 78 underwent uterine artery embolization due to intraoperative or postoperative bleeding.The uterus was successfully preserved in all patients.Except for five cases of right lower extremity arterial thrombosis,the remaining patients did not have postoperative lower extremity arteriovenous thrombosis,renal insufficiency,late postpartum hemorrhage,ectopic embolism,spinal cord or peripheral nerve damage,pelvic infection,or other serious complications.The mean operative time was 65.3(±14.5)min.The mean intraoperative blood loss was620(±570)ml.Ninety-six patients(15.4%,96/623)were treated with blood transfusion,and the average amount of blood transfused was 750(±400)ml.The average number of hospitalization days was 6.8(±3.4)days,the average time of fetal ray exposure was 5.2(±1.6)s,and the average radiation dose was 4.1(±2.7)m Gy.The neonatal Apgar score,was 8.4(±0.6)points at 1 min,and 9.6(±0.4)points at 5 min.In the follow-up to May 31,2019,29 patients were lost to follow-up,96 were lactating,and 498 were menstruating.Except for the cases lost to follow-up,the remaining 596 surviving newborns(including 2 twins)showed no abnormalities at the 42-day postnatal outpatient follow-up examination.Conclusion:Balloon occlusion of the abdominal aorta is a safe and effective method for the treatment of pernicious placenta previa with placenta accreta.

Application of abdominal aortic balloon occlusion followed by uterine artery embolization for the treatment of pernicious placenta previa complicated with placenta accreta during cesarean section

Objective:This study aimed to investigate the clinical effects of abdominal aortic balloon occlusion followed by uterine artery embolization for the treatment of pernicious placenta previa complicated with placenta accreta during cesarean section.Methods:We performed a retrospective analysis of the clinical data for 623 patients who experienced pernicious placenta previa complicated with placenta accreta and received treatment in our hospital from January 2013 to January 2019.All patients underwent abdominal aortic balloon occlusion before their cesarean section.Seventyeight patients received bilateral uterine artery embolization,and among them,placenta accreta was found at the opening of the cervix in 13 patients.Due to suturing difficulty after the removal of the placenta,gauze packing was used to temporarily compress the hemorrhage.As soon as the uterus was sutured,emergent bilateral uterine artery embolization was performed.Active bleeding was noted in the remaining 65 patients when the lower part of the uterus was pressed after the placenta was removed and the uterus was sutured,therefor,bilateral uterine artery embolization was performed urgently.Results:Of the 623 patients,545 patients underwent only abdominal aortic balloon occlusion and 78 patients underwent additional emergent bilateral uterine artery embolization due to hemorrhaging during or after their cesarean section.No hysterectomies were performed.In the 78 patients,the amount of bleeding was 800-3,200 ml with an average of 1,650 ml during the operation;the volume of blood transfused was 360-1,750 ml(average:960 ml).The fetal fluoroscopy time was 3–8 s(average:5 s).The dose of radiation exposure was(4.2±2.9) m Gy.Fetal appearance,pulse,grimace,activity,and respiration(Apgar) score were normal.No serious complications were observed during or after the operation in the follow-up visits.Conclusion:For patients with pernicious placenta previa complicated with placenta accreta who experience active bleeding after cesarean section and abdominal aortic balloon occlusion,bilateral uterine artery embolization can effectively reduce blood loss and requirement of blood transfusion during the operation,and lowers the risk of hysterectomy.

Fasudil alleviates LPS-induced lung injury by restoring aquaporin 5 expression and inhibiting inflammation in lungs

Fasudil, a selective rho kinase(ROCK) inhibitor, has been reported to play a beneficial role in systemic inflammation in acute lung injury, but its mechanism for ameliorating pulmonary edema and inflammation remains unclear. Using hematoxylin-and-eosin(H&E) staining, immunohistochemistry, enzyme-linked immunosorbent assay,quantitative real time PCR and Western blotting, we found that fasudil attenuated LPS-induced lung injury, decreased lung edema, and suppressed inflammatory responses including leukocyte infiltration and IL-6 production. Further,fasudil upregulated LPS-induced aquaporin 5 reduction and inhibited NF-κB activation in the lungs of mice. Our results suggest that fasudil could restore the expression of aquaporin 5 to eliminate LPS-induced lung edema and prevent LPS-induced pulmonary inflammation by blocking the inflammatory pathway. Collectively, blockade of the ROCK pathway by fasudil may be a potential strategy for the treatment of acute lung injury.

Molecular detection of Xanthomonas oryzae pv.oryzae, Xanthomonas oryzae pv. oryzicola, and Burkholderia glumae in infected rice seeds and leaves

The polymerase chain reaction(PCR) is particularly useful for plant pathogen detection. In the present study, multiplex PCR and SYBR Green real-time PCR were developed to facilitate the simultaneous detection of three important rice pathogens, Xanthomonas oryzae pv.oryzae, X. oryzae pv. oryzicola, and Burkholderia glumae. The unique PCR primer sets were designed from portions of a putative glycosyltransferase gene of X. oryzae pv. oryzae, an Avr Rxo gene of X. oryzae pv. oryzicola, and an internal transcribed spacer(ITS) sequence of B. glumae. Using a multiplex PCR assay, X. oryzae pv. oryzae, X. oryzae pv. oryzicola, and B. glumae were detected in one PCR reaction that contained the newly developed primer set mix. Using SYBR Green real-time PCR assays, X. oryzae pv. oryzae, X. oryzae pv. oryzicola, and B. glumae were detected at 1, 1, and 10 fg μL-1, respectively. These newly designed molecular assays are sensitive and could be reliable tools for pathogen detection and disease forecasting.

Approximate analytical solution in slow-fast system based on modified multi-scale method

A simple,yet accurate modi?ed multi-scale method(MMSM)for an approximately analytical solution in nonlinear oscillators with two time scales under forced harmonic excitation is proposed.This method depends on the classical multi-scale method(MSM)and the method of variation of parameters.Assuming that the forced excitation is a constant,one could easily obtain the approximate analytical solution of the simpli?ed system based on the traditional MSM.Then,this solution for the oscillator under forced harmonic excitation could be established after replacing the harmonic excitation by the constant excitation.To certify the correctness and precision of the proposed analytical method,the van der Pol system with two scales subject to slowly periodic excitation is investigated;this system presents rich dynamical phenomena such as spiking(SP),spiking-quiescence(SP-QS),and quiescence(QS)responses.The approximate analytical expressions of the three types of responses are given by the MMSM,and it can be found that the precision of the new analytical method is higher than that of the classical MSM and better than that of the harmonic balance method(HBM).The results obtained by the present method are considerably better than those obtained by traditional methods,quantitatively and qualitatively,particularly when the excitation frequency is far less than the natural frequency of the system.

An improved specimen preparation method for marine shallow gasbearing sand sediments and its validations

Instabilities of shallow gas-charged seabed are potential geological hazards in ocean engineering.In practice,the conventional field sampling techniques failed to obtain undisturbed gas-bearing sediments from the seabed for laboratory mechanical testing because of sensitive gas exsolution and escape from sediments.However,preparation of representative remoulded gas-charged specimens is a challenging issue,because it is rather difficult to quantitatively control the gas content and obtain uniform distribution of gas bubbles within the specimen.Given the above problems,this work proposes a reliable approach to reconstitute the high-saturation specimen of gas-charged sediments in the laboratory by an improved multifunction integrated triaxial apparatus(MITA).This apparatus is developed based on an advanced stress path triaxial system by introducing a temperature-controlled system and a wavemonitoring system.The temperature-controlled system is used to accurately mimic the in situ environments of sediments in the seabed.The wave-monitoring system is utilized to identify exsolution point of free gas and examine the disturbance of gas to specimens during gas exsolution.The detailed procedure of gassy specimen preparation is introduced.Then,the quality of prepared specimens using our improved apparatus is validated by the high-resolution micro-X-ray computed tomography(mCT)scanning test,from which bubble occurrence and size distribution within the gassy sand specimen can be obtained;and preliminary mechanical tests on gassy sand specimens with various initial saturation degrees are performed.The proposed specimen preparation procedure succeeds in proving the postulated occurrence state of gas bubbles in coarse-grained sediments and accurately controlling the gas content.

Characteristics of alveolar macrophages in bronchioalveolar lavage fluids from active tuberculosis patients identified by single-cell RNA sequencing

Tuberculosis(TB),is an infectious disease caused by Mycobacterium tuberculosis(M.tuberculosis),and presents with high morbidity and mortality.Alveolar macrophages play an important role in TB pathogenesis although there is heterogeneity and functional plasticity.This study aimed to show the characteristics of alveolar macrophages from bronchioalveolar lavage fluid(BALF)in active TB patients.Single-cell RNA sequencing(scRNA-seq)was performed on BALF cells from three patients with active TB and additional scRNA-seq data from three healthy adults were established as controls.Transcriptional profiles were analyzed and compared by differential gene expression and functional enrichment analysis.We applied pseudo-temporal trajectory analysis to investigate correlations and heterogeneity within alveolar macrophage subclusters.Alveolar macrophages from active TB patients at the single-cell resolution are described.We found that TB patients have higher cellular percentages in five macrophage subclusters.Alveolar macrophage subclusters with increased percentages were involved in inflammatory signaling pathways as well as the basic macrophage functions.The TB-increased alveolar macrophage subclusters might be derived from M1-like polarization state,before switching to an M2-like polarization state with the development of M.tuberculosis infection.Cell-cell communications of alveolar macrophages also increased and enhanced in active TB patients.Overall,our study demonstrated the characteristics of alveolar macrophages from BALF in active TB patients by using scRNA-seq.

A Review of the Design and Architecture of Starch-Based Dietary Foods

Carbohydrates,which are mostly present in sugar,starch,and fiber,are one of the main ingredients of food and the primary source of energy in the human diet.Among these three main sources,starch stands out as one of the most abundant reserves of carbohydrates.Investigating starch would not only enhance our understanding of the functionality of starch in the human body but also aid in the design of novel starch-based dietary foods.The present review first provides a state-of-the-art understanding of the various classifications of dietary starches,including rapidly digesting starch(RDS),slowly digesting starch(SDS),and resistant starch(RS).Moreover,both the in vivo and in vitro determination methods of the digestibility of starch-based dietary foods are discussed.Based on the current understanding,present research strategies to design novel starch-based dietary foods through either the direct addition of modified starch or the alteration of processing conditions are highlighted.Furthermore,certain perspectives related to the future research directions of starch-based foods are also included.

Efficacy of patient-controlled hydromorphone analgesia in those undergoing uterine fibroid artery embolization via the right radial artery

Objective: To evaluate the efficacy and safety of patient-controlled analgesia(PCA) with hydromorphone as perioperative analgesia during uterine artery embolization(UAE) via the right radial artery.Patients and methods: A total of 33 patients with uterine fibroids, who underwent UAE at the authors’ hospital between June 2021 and March 2022, were selected. Hydromorphone(10 mg) was dispensed into a 100 ml PCA pump with normal saline. Pump administration was initiated 15 min before the start of the procedure, and the intraoperative dose was adjusted according to patient pain level. A numerical rating scale was used to evaluate pain immediately after embolization, 5 min after embolization, at the end of the procedure, and 6, 12, 24, 48, and 72 h after the procedure. Side effects were also observed.Results: Thirty-three patients underwent uterine artery embolization via the right radial artery. Patient pain was well controlled at all time points surveyed, and patients reported satisfaction with analgesia. The median length of hospital stay was 5 days. There were 7 cases of adverse reactions, but no serious side effects were observed.Conclusion: Patients reported positive experiences with arterial embolization of uterine fibroids via the right radial artery. Hydromorphone PCA effectively controlled pain. The PCA pump is easy to operate, has a low incidence of adverse reactions, and offers economic benefits at the patient and institutional levels.

Carbon foams prepared from coal tar pitch for building thermal insulation material with low cost

A new approach is provided to resolve the large-scale applications of coal tar pitch. Carbon foams with uniform pore size are prepared at the foaming pressure of normal pressure using coal tar pitch as raw materials. The physical and chemical performance of high softening point pitch(HSPP) can be regulated by vacuumizing owing to the cooperation of vacuumizing and polycondensation. Results indicate that the optimum softening point and weight ratio of quinoline insoluble are about 292℃ and 65.7%, respectively. And the optimum viscosity of HSPP during the foaming process is distributed in the range of 1000-10000 Pa·s. The resultant carbon foam exhibits excellent performance, such as uniform pore structure, high compressive strength(4.7 MPa), low thermal conductivity(0.07 W·m^(-1) ·K^(-1)), specially, it cannot be fired under the high temperature of 1200 ℃.Thus, this kind of carbon foam is a potential candidate for thermal insulation material applied in energy saving building.

Molecular characterization and expression analysis of three homoeologous Ta14S genes encoding 14-3-3 proteins in wheat(Triticum aestivum L.)

The purpose of this study was to characterize Ta14 S homoeologs and assess their functions in wheat seed development.The genomic and c DNA sequences of three Ta14 S homoeologous genes encoding 14-3-3 proteins were isolated.Sequence analysis revealed that the three homoeologs consisted of five exons and four introns and were very highly conserved in the coding regions and in exon/intron structure,whereas the c DNA sequences were variable in the 5′ and 3′-UTR.The three genes,designated as Ta14S-2A,Ta14S-2B and Ta14S-2D,were located in homoeologous group 2 chromosomes.The polypeptide chains of the three Ta14 S genes were highly similar.These genes were most homologous to Hv14 A from barley.Real-time quantitative PCR indicated that the three Ta14 S genes were differentially expressed in different organs at different developmental stages and all exhibited greater expression in primary roots of 1-day-old germlings than in other tissues.Comparison of the expression patterns of the three homoeologous genes at different times after pollination also revealed that their expression was developmentally regulated.The transcription of Ta14S-2B was clearly higher during seed germination,whereas expressions of Ta14S-2A and Ta14S-2D were up-regulated at the beginning of seed imbibition(0–12 h),but declined thereafter.The results suggested that the three Ta14 S homoeologous genes have regulatory roles in seed development and germination.

Post-liquefaction shearing behaviour of saturated gravelly soils: Experimental study and discrete element simulation

To investigate the post-liquefaction shearing behaviour of saturated gravelly soil,laboratory tests were conducted using a staticedynamic multi-purpose triaxial apparatus.In addition,numerical simulations using the discrete element method(DEM)were performed to preliminarily understand the micromechanism of gravelly soil in monotonic loading after liquefaction.The influences of dry density,initial confining stress and degree of liquefaction on the post-liquefaction shearing behaviour of gravelly soil were discussed,and the evolution of the micro-parameters of the granular system was also analysed.The results show that the stressestrain responses of gravelly soil after liquefaction can be divided into three stages:(1)low strength stage,(2)super-linear strength recovery stage,and(3)sublinear strength recovery stage,which are distinctly different from those of the general saturated gravelly soil without previous cyclic loading.The initial state and prior dynamic stress history have significant influences on the post-liquefaction shearing behaviour of gravelly soil.The DEM simulation revealed that the average coordination number sharply increases,the contact normal shows an obvious orientation distribution,and the destroyed force chain backbones are reconstructed in the monotonic reloading process after liquefaction.The evolution of the micro-parameters of the granular system clearly reflects the interior interaction process and micro-mechanisms in the particles during the three different stages of the macro-mechanical behaviour of gravelly soil.