The leucine-rich repeat(LRR)protein family is involved in a variety of fundamental metabolic and signaling processes in plants,including growth and defense responses.LRR proteins can be divided into two categories:tho...The leucine-rich repeat(LRR)protein family is involved in a variety of fundamental metabolic and signaling processes in plants,including growth and defense responses.LRR proteins can be divided into two categories:those containing LRR domains along with other structural elements,which are further subdivided into five groups,LRR receptor-like kinases,LRR receptor-like proteins,nucleotide-binding site LRR proteins,LRR-extensin proteins,and polygalacturonase-inhibiting proteins,and those containing only LRR domains.Functionally,various LRR proteins are primarily involved in plant development and responses to environmental stress.Notably,the LRR protein family plays a central role in signal transduction pathways related to stress adaptation.In this review,we classify and analyze the functions of LRR proteins in plants.While extensive research has been conducted on the roles of LRR proteins in disease resistance signaling,these proteins also play important roles in abiotic stress responses.This review highlights recent advances in understanding how LRR proteins mediate responses to biotic and abiotic stresses.Building upon these insights,further exploration of the roles of LRR proteins in abiotic stress resistance may aid efforts to develop rice varieties with enhanced stress and disease tolerance.展开更多
In this study,AZ31 Mg alloy sheets were processed by a severe plastic deformation(SPD)technique called forging-bending repeated deformation(FBRD).The effect on the microstructure and microhardness of AZ31 Mg alloy thr...In this study,AZ31 Mg alloy sheets were processed by a severe plastic deformation(SPD)technique called forging-bending repeated deformation(FBRD).The effect on the microstructure and microhardness of AZ31 Mg alloy through FBRD was investigated with increasing temperature treatment and a 90°cross route.The results reveal that the effective strain increases with the number of passes.The flow uniformity is effectively enhanced due to alterations in shear deformation direction.After four passes of deformation,the average grain size is refined by 79.3%compared to the initial specimen.The grain refinement mechanism predominantly originates from the synergistic effects of discontinuous dynamic recrystallization(DDRX),continuous dynamic recrystallization(CDRX),and twinning-induced recrystallization(TDRX).The formation of{1012}extension twins(ET)significantly contributes to coarse grain subdivision and plastic deformation coordinated.Furthermore,pyramidal<c+a>slip activation effectively enhances the plasticity of Mg alloys.By post four-pass processing,the alloy exhibits a microhardness of 81.9HV,primarily governed by fine grain strengthening and dislocation strengthening mechanisms.展开更多
Industrial robots are integral to modern manufacturing systems,enabling high precision,high throughput,and flexibility.However,errors in accuracy and repeatability,which arise from a variety of sources such as mechani...Industrial robots are integral to modern manufacturing systems,enabling high precision,high throughput,and flexibility.However,errors in accuracy and repeatability,which arise from a variety of sources such as mechanical wear,calibration issues,and environmental factors,can significantly impact the performance of industrial robots.This paper aims to explore the theoretical modeling of errors in industrial robot systems and propose compensation strategies to enhance their accuracy and repeatability.Key factors contributing to errors,such as kinematic,dynamic,and environmental influences,are discussed in detail.Additionally,the paper explores various compensation techniques,including geometric error compensation,dynamic compensation,and adaptive control approaches.Through the integration of error modeling and compensation methods,industrial robots can achieve improved performance,ensuring higher operational efficiency and product quality.The paper concludes by highlighting the challenges and future research directions for improving the accuracy and repeatability of industrial robots in practical applications.展开更多
BACKGROUND Repeated application of the Pringle maneuver is a key obstacle to safe minimally invasive repeat liver resection(MISRLR).However,limited technical guidance is available.AIM To study the utility of newly dev...BACKGROUND Repeated application of the Pringle maneuver is a key obstacle to safe minimally invasive repeat liver resection(MISRLR).However,limited technical guidance is available.AIM To study the utility of newly developed Pringle taping method guided by liver surface in MISRLR.METHODS We retrospectively reviewed 72 cases of MISRLR performed by a single surgeon at two centers from August 2015 to July 2024.Beginning in October 2019,a liver surface-guided encirclement of hepatoduodenal ligament(LSEH)was used for repeat Pringle taping.Perioperative outcomes including Pringle taping success,operative time,blood loss,conversion rate,morbidity,and mortality were assessed.RESULTS Laparoscopic and robotic approaches were used in 63 patients and 9 patients,respectively.The median operative time,blood loss,and hospital stay were 331.5 minutes,70 mL,and 8 days,respectively.Open conversion occurred in two cases(2.8%)due to severe adhesions and right renal vein injury.Clavien-Dindo grade≥III complications occurred in 5.6%of cases with no mortality.Anti-adhesion barriers were used in 54 patients(75.0%).LSEH was attempted in 57 cases,improving Pringle taping success from 33.0%to 91.4%(P<0.001).LSEH succeeded in all patients with prior open liver resection(n=11).Among 6 patients in whom LSEH failed,3 patients(50.0%)had undergone a third liver resection,and 1 patient had a history of distal gastrectomy with choledochoduodenostomy.CONCLUSION The newly developed LSEH technique for Pringle taping in MISRLR was feasible,enhancing safety and reproducibility even in patients with a history of open liver resection.展开更多
目的:分析江苏省汉族人群亲子鉴定中39个短串联重复序列(short tandem repeat,STR)基因座的突变特征。方法:选取2019年1月—2024年12月南京医科大学第一附属医院司法鉴定所受理的6812例亲子鉴定案例,采用GoldenEye^(TM) DNA身份鉴定系...目的:分析江苏省汉族人群亲子鉴定中39个短串联重复序列(short tandem repeat,STR)基因座的突变特征。方法:选取2019年1月—2024年12月南京医科大学第一附属医院司法鉴定所受理的6812例亲子鉴定案例,采用GoldenEye^(TM) DNA身份鉴定系统检测39个STR基因座的突变情况,对突变率、突变来源和步数进行统计分析。结果:在6812例认定亲子关系的案例中,三联体1680例,二联体5132例。共发现214例突变案例,总突变率2.52%。其中,D12S391基因座突变率最高,达0.3297%(28/8492),其次为Penta E、FGA、D21S11、D18S51、D3S1358基因座,突变率均在0.20%以上。突变来源分析中,父源突变189例,母源突变20例,不明原因突变5例,父源突变显著高于母源(P<0.001)。203例(94.86%)突变为一步突变,二步突变9例,FGA和D21S11基因座三步突变各1例。结论:亲子鉴定中39个STR基因座总突变率较高,达2.52%,具有性别和地区差异,在亲子鉴定实践中需加以重视,该结果为江苏地区汉族人群STR基因座突变情况提供数据支撑,有助于提升复杂亲缘关系鉴定的准确性。展开更多
The exciting source of the active source repeated monitoring is located in the Xiliushui Reservoir in Zhangye,Gansu Province. The system began operating normally on July 9,2015,and we had completed a period of 40 days...The exciting source of the active source repeated monitoring is located in the Xiliushui Reservoir in Zhangye,Gansu Province. The system began operating normally on July 9,2015,and we had completed a period of 40 days of continuous excitation experiment before November 10,2015. Our results reveal that the airgun source has good consistency and repeatability,and the detective system of active source can record signal clearly. The construction of active source repeated exploration projects has achieved some results,which can provide valuable experience for the research of active source repeated exploration. The observation data we obtained makes it possible to follow the temporal and spatial variations of the deep structure of the Qilian Mountain areas.展开更多
The feasibility of using different generations of recycled fine aggregate（RFA） in structural concrete in a chloride environment was evaluated by studying the performance of the RFA and the corresponding concrete. Th...The feasibility of using different generations of recycled fine aggregate（RFA） in structural concrete in a chloride environment was evaluated by studying the performance of the RFA and the corresponding concrete. The different generations of RFA were recycled by following the cycle of ‘concrete-waste concrete-fine aggregate-concrete＇. The properties of three generations of repeatedly recycled fine aggregate（RRFA） were systematically investigated, and we focused on the compressive strength and splitting tensile strength and chloride ion permeability of the related structural concretes with 25%, 75%, and 100% replacement of natural fine aggregates with RFA. The results indicated that the quality of RRFA presents a trend of slow deterioration, but the overall performance of all RRFA still fulfils the quality requirements of recycled fine aggregate for structural concrete. All RRFA concretes achieved the target compressive strength of 40 MPa after 28 days except for the second generation of the recycled aggregate concrete and the third generation of the recycled aggregate concrete with 100% replacement, and all the concrete mixes achieved the target compressive strength after 90 days. The insights obtained in this study demonstrate the feasibility of using at least three generations of RRFA for the production of normal structural concrete with a design service life of 100 years in a chloride environment.展开更多
Repeatedly unidirectional bending(RUB) was applied to the magnesium alloy sheet to improve the basal texture.The effect of RUB temperature on resulting structure and room temperature properties was investigated.The te...Repeatedly unidirectional bending(RUB) was applied to the magnesium alloy sheet to improve the basal texture.The effect of RUB temperature on resulting structure and room temperature properties was investigated.The texture components of the sheet undergoing RUB at recovery temperature were similar to those of the sheet undergoing RUB at room temperature(RT).As the RUB temperature increased to above recrystallization temperature,the texture components became more disperse and the pyramidal components increased.With the increase of RUB temperature,the grain size near the surface of the sheets undergoing RUB tended to grow up.When the sheets were processed by RUB at medium-high temperature followed by annealing at 533 K,the yield strength and fracture elongation were lower than those of the cold rolled sheet;however,the Erichsen value was slightly higher than that of the cold rolled sheet.The sheet undergoing RUB at RT followed by annealing at 533 K represented the best mechanical properties.展开更多
Weedy rice exerts a severe impact on rice production by competing for sunlight, water and nutrients. This study assayed the population structure, genetic diversity and origin of Northeast Asia weedy rice by using 48 s...Weedy rice exerts a severe impact on rice production by competing for sunlight, water and nutrients. This study assayed the population structure, genetic diversity and origin of Northeast Asia weedy rice by using 48 simple sequence repeat markers. The results showed that weedy rice in Northeast Asia had a high genetic diversity, with Shannon＇s diversity index （I） of 0.748 and the heterozygosity （He） of 0.434. In each regional population, I value varied widely. The widest range of I （0.228-0.489） was observed in the weedy rice of Eastern China, which was larger than that of Northeast China and Korea （0.168-0.270）. The F-statistics of regional populations （Fis, Fit and Fst） also showed higher values in the weedy rice of Eastern China than those of Northeast China and Korea All weedy rice accessions were grouped into two clusters in the unweighted pair group method with arithmetic mean cluster analysis dendrogram, namely Eastern China branch and Northeastern China plus Korea branch. There was significant differentiation in genetic characteristics in weedy rice of northeastern and eastern Asia, especially in Eastern China.展开更多
A new repeated upsetting-extrusion (RUE) process was proposed to improve the microstructure and the mechanical properties of Mg alloys. The effects of deformation temperature on the microstructure and microhardness of...A new repeated upsetting-extrusion (RUE) process was proposed to improve the microstructure and the mechanical properties of Mg alloys. The effects of deformation temperature on the microstructure and microhardness of RUEed AQ80 Mg alloy were studied. The results showed that Mg alloy is subjected to sufficient corner shear deformation, upsetting deformation, and extrusion deformation, resulting in a large and uniformly distributed effective strain after RUE deformation. The microstructure is refined to an average grain size of 2.1 μm by the continuous dynamic recrystallization (CDRX) mechanism at 250 °C. As the temperature increases to 300 °C, the discontinuous dynamic recrystallization (DDRX) mechanism is activated and the average grain size is refined to 1.6 µm by the combined effect of CDRX and DDRX. In comparison to their parent grains, the orientations of the CDRXed grains show a clearly preferred orientation, but those of the DDRXed grains are completely different. At 350 °C, {10-12} extension twins appear in the microstructure, and the twinning-induced recrystallization (TDRX) mechanism plays an important role in grain refinement. With the two strengthening mechanisms of fine-grained strengthening and dislocation strengthening, the microhardness of the 250 °C sample is greatly improved, with an increase of about 35.1% compared to the initial sample.展开更多
Puccinia striiformis f. sp. tritici （Pst） is the obligate biotrophic fungus responsible for stripe rust wheat. In this study, we developed and characterized 20 polymorphic microsatelUte markers from the genomic sequ...Puccinia striiformis f. sp. tritici （Pst） is the obligate biotrophic fungus responsible for stripe rust wheat. In this study, we developed and characterized 20 polymorphic microsatelUte markers from the genomic sequence of an isolate of Chinese Pst race C^32. Polymorphism at each simple sequence repeat （SSR） locus was determined using 32 Pst isolates from 7 countries. The number of alleles varied from 2 to 7 across isolates, and the observed and expected heterozygosities ranged from 0.33 to 0.97 （mean 0.62） and 0.23 to 0.73 （mean 0.51 ）, respectively. As expected the genomic SSR markers were more polymorphic than the expressed sequence tag （EST）-SSR markers developed previously. These markers will be more useful for population genetics and molecular genetics studies in Pst.展开更多
AIM:To evaluate the influence of MUC1 mucin variable number of tandem repeats (VNTR) variability on H pylori adhesion to gastric cells. METHODS: Enzyme linked immunosorbent assay (ELISA)-based adhesion assays were per...AIM:To evaluate the influence of MUC1 mucin variable number of tandem repeats (VNTR) variability on H pylori adhesion to gastric cells. METHODS: Enzyme linked immunosorbent assay (ELISA)-based adhesion assays were performed to measure the adhesion of different H pylori strains (HP26695 and HPTx30a) to gastric carcinoma cell lines (GP202 and MKN45) and GP202 clones expressing recombinant MUC1 with different VNTR lengths. RESULTS: Evaluation of adhesion results shows that H pylori pathogenic strain HP26695 has a significantly higher (P < 0.05) adhesion to all the cell lines and clones tested, when compared to the non-pathogenic strain HPTx30a. Bacteria showed a significantly higher (P < 0.05) adhesion to the GP202 cell line, when compared to the MKN45 cell line. Furthermore, both strains showed a significantly higher (P < 0.05) adhesion to GP202 clones with larger MUC1 VNTR domains. CONCLUSION: This work shows that MUC1 mucin variability conditions H pylori binding to gastric cells. The extent of bacterial adhesion depends on the size of theMUC1 VNTR domain. The adhesion is further dependent on bacterial pathogenicity and the gastric cell line. MUC1 mucin variability may contribute to determine H pylori colonization of the gastric mucosa.展开更多
Very fast transient over-voltage （VFTO）, induced by disconnector operations in gas- insulated switchgears, has become the limiting dielectric stress at ultra-high voltage levels. Much work has been done to investiga...Very fast transient over-voltage （VFTO）, induced by disconnector operations in gas- insulated switchgears, has become the limiting dielectric stress at ultra-high voltage levels. Much work has been done to investigate single-strike waveforms of VFTO. However, little study has been carried out investigating the repeated strike process, which would influence VFTO significantly. In this paper, we carried out 450 effective experiments in an ultra-high voltage test circuit, and conducted calculations through the Monte Carlo simulation method, to investigate the repeated strike process. Firstly, the mechanism of the repeated strike process is proposed, based on the ex- perimentai results. Afterwards, statistical breakdown characteristics of disconnectors are obtained and analyzed. Finally, simulations of the repeated strike process are conducted, which indicate that the dielectric strength recovery speed and polarity effect factor have a joint effect on VFTO. This study enhances the understanding of the nature of VFTO, and may help to optimize the disconnector designed to minimize VFTO.展开更多
In the recent past,the potential benefits of wraparound geosynthetic reinforcement technique for constructing the reinforced soil foundations have been reported.This paper presents the experimental study on the behavi...In the recent past,the potential benefits of wraparound geosynthetic reinforcement technique for constructing the reinforced soil foundations have been reported.This paper presents the experimental study on the behaviour of model strip footing resting on sandy soil bed reinforced with geosynthetic in wraparound and planar forms under monotonic and repeated loadings.The geosynthetic layers were laid according to the reinforcement ratio to minimise the scale effect.It is found that for the same amount of reinforcement material,the wraparound reinforced model resulted in less settlement in comparison to planar reinforced models.The efficiency of wraparound reinforced model increased with the increase in load amplitude and the rate of total cumulative settlement substantially decreased with the increase in number of load cycles.The wraparound reinforced model has shown about 45% lower average total settlement in comparison to unreinforced model,while the double-layer reinforced model has about 41% lower average total settlement at the cost of approximately twice the material and 1.5 times the occupied land width ratio.Moreover,wraparound models have shown much greater stability in comparison to their counterpart models when subjected to incremental repeated loading.展开更多
BACKGROUND Repeated endoscopic probe dilatation is the most preferred treatment for esophageal stenosis which may cause high levels of symptom distress in the patient’s home rehabilitation stage.AIM To explore the ch...BACKGROUND Repeated endoscopic probe dilatation is the most preferred treatment for esophageal stenosis which may cause high levels of symptom distress in the patient’s home rehabilitation stage.AIM To explore the changes in the symptom distress level and its correlation with the dilation effect in patients with esophageal carcinoma undergoing repeated dilations for lumen stenosis.METHODS The difference(R2-R1)between the diameter of the esophageal stenosis opening(R1)of the patients before dilation(R1)and after dilation(R2)was calculated to describe the extent and expansion of the esophageal stenosis before and after dilation.The M.D.Anderson Symptom Inventory was used to describe the symptom distress level of patients with dilation intermittence during their stay at home and to explore the correlation between the dilation effect and symptom distress level.RESULTS The diameter of the esophagus(R1)increased before each dilation in patients undergoing esophageal dilation(P<0.05).The diameter(R2)increased after dilation(P<0.05);the dilation effect(R2-R1)decreased with the number of dilations(P<0.05).The total symptom distress score significantly increased with the number of dilations(P<0.05).The symptom distress scores of the patients were negatively correlated(P<0.05)with the previous dilation effect(R2-R1)and the esophageal diameter(R2)after the previous dilation.After the 1 st to 4 th dilations,the patient’s symptom distress score was negatively correlated with the esophageal diameter(R12)before the next dilation,while there was no significant correlation(P>0.05)with the other dilations.CONCLUSION In patients who have undergone repeated dilations,better effect stands for lower symptom distress level and the increase in symptom distress has a prompt effect on the severity of the next occurrence of restenosis.展开更多
In this study, AZ31 Mg alloy was processed by a new severe plasticity deformation methodology with multi-pass lowered temperature, and the deformation behavior and microstructure evolution were investigated by finite ...In this study, AZ31 Mg alloy was processed by a new severe plasticity deformation methodology with multi-pass lowered temperature, and the deformation behavior and microstructure evolution were investigated by finite element method and electron back-scattered diffraction technique and hardness. The results show that with the increase of deformation pass, the strain gradually springs, and its interval distribution tends to homogenize. Meanwhile, the effective strain increases dramatically with the shear force sudden upgrade in the deformation process. Moreover, the new deformation technique can refine grain size remarkably. With the passes on, {10-12} tensile twins behavior and the pyramidal < c + a > slip are triggered more frequently, leading to the completeness of dynamic recrystallization (DRX) gradually, which weaken and disperse the basal texture obviously. Besides, the standard deviation of hardness is getting smaller, and the maximum can reach 78.40 HV on average, which can be attributed to the even large strain distribution, complete DRX, and the high geometrically necessary dislocation.展开更多
To investigate the abnormal ground pressures and roof control problem in fully mechanized repeated mining of residual coal after room and pillar mining, the roof fracture structural model and mechanical model were dev...To investigate the abnormal ground pressures and roof control problem in fully mechanized repeated mining of residual coal after room and pillar mining, the roof fracture structural model and mechanical model were developed using numerical simulation and theoretical analysis. The roof fracture characteristics of a repeated mining face were revealed and the ground pressure law and roof supporting condi- tions of the repeated mining face were obtained. The results indicate that when the repeated mining face passes the residual pillars, the sudden instability causes fracturing in the main roof above the old goal and forms an extra-large rock block above the mining face. A relatively stable ＂Voussoir beam＂ structure is formed after the advance fracturing of the main roof. When the repeated mining face passes the old goaf, as the large rock block revolves and touches gangue, the rock block will break secondarily under overburden rock loads. An example calculation was performed involving an integrated mine in Shanxi province, results showed that minimum working resistance values of support determined to be reason- able were respectively 11,412 kN and 10,743 kN when repeated mining face passed through residual pillar and goaf. On-site ground pressure monitoring results indicated that the mechanical model and support resistance calculation were reasonable.展开更多
目的通过对236例流产物进行低深度全基因组拷贝数变异检测(copy number variation sequencing,CNV-seq)及短串联重复序列(short tandem repeats,STR)连锁分析检测,探讨其在流产物染色体异常检测中的临床应用价值。方法采用CNV-seq和STR...目的通过对236例流产物进行低深度全基因组拷贝数变异检测(copy number variation sequencing,CNV-seq)及短串联重复序列(short tandem repeats,STR)连锁分析检测,探讨其在流产物染色体异常检测中的临床应用价值。方法采用CNV-seq和STR连锁分析对2021年3月-2024年8月于郑州大学第二附属医院产前诊断中心就诊的236例自然流产患者的流产物样本进行检测,确定具有临床意义的染色体异常并对其进行分析。结果6例流产物因严重母源污染退出研究,剩余230例流产物染色体异常的阳性率为62.61%(144/230),其中染色体非整倍体110例(69.44%),多倍体7例(4.86%),拷贝数变异27例(18.75%)。染色体非整倍体中以常染色体三体最为常见,其中16-三体最常见,其次是21-三体。高龄产妇染色体异常率显著高于低龄产妇,早期流产组染色体异常发生率显著高于晚期流产组,均以染色体非整倍体异常为主。结论染色体非整倍体是导致自然流产最常见的原因,孕妇的妊娠年龄与胎儿常染色体三体的发生密切相关。CNV-seq联合STR连锁分析对于流产物的染色体分析高效可靠,可作为流产物遗传学分析的常规方法。展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.32072048 and U2004204)National Key Research and Development Program of China(Grant No.2023YFF1001200)+2 种基金China Rice Research Institute Basal Research Fund(Grant No.CPSIBRF-CNRRI-202404)Academician Workstation of National Nanfan Research Institute(Sanya),Chinese Agricultural Academic Science(CAAS),(Grant Nos.YBXM2422 and YBXM2423)Agricultural Science and Technology Innovation Program of CAAS,China.
文摘The leucine-rich repeat(LRR)protein family is involved in a variety of fundamental metabolic and signaling processes in plants,including growth and defense responses.LRR proteins can be divided into two categories:those containing LRR domains along with other structural elements,which are further subdivided into five groups,LRR receptor-like kinases,LRR receptor-like proteins,nucleotide-binding site LRR proteins,LRR-extensin proteins,and polygalacturonase-inhibiting proteins,and those containing only LRR domains.Functionally,various LRR proteins are primarily involved in plant development and responses to environmental stress.Notably,the LRR protein family plays a central role in signal transduction pathways related to stress adaptation.In this review,we classify and analyze the functions of LRR proteins in plants.While extensive research has been conducted on the roles of LRR proteins in disease resistance signaling,these proteins also play important roles in abiotic stress responses.This review highlights recent advances in understanding how LRR proteins mediate responses to biotic and abiotic stresses.Building upon these insights,further exploration of the roles of LRR proteins in abiotic stress resistance may aid efforts to develop rice varieties with enhanced stress and disease tolerance.
基金Project(52174362)supported by the National Natural Science Foundation of ChinaProject(2023JJ10020)supported by the Natural Science Foundation of Hunan Province,China+2 种基金Project(2024RC7002)supported by the Science and Technology Innovation Program of Hunan Province,ChinaProject(2024CY2-GJHX-71)supported by the Shaanxi Provincial Key R&D Program,ChinaProject supported by the Yancheng“Talent Plan of Yellow Sea Pearl”for Leading Talent Project,China。
文摘In this study,AZ31 Mg alloy sheets were processed by a severe plastic deformation(SPD)technique called forging-bending repeated deformation(FBRD).The effect on the microstructure and microhardness of AZ31 Mg alloy through FBRD was investigated with increasing temperature treatment and a 90°cross route.The results reveal that the effective strain increases with the number of passes.The flow uniformity is effectively enhanced due to alterations in shear deformation direction.After four passes of deformation,the average grain size is refined by 79.3%compared to the initial specimen.The grain refinement mechanism predominantly originates from the synergistic effects of discontinuous dynamic recrystallization(DDRX),continuous dynamic recrystallization(CDRX),and twinning-induced recrystallization(TDRX).The formation of{1012}extension twins(ET)significantly contributes to coarse grain subdivision and plastic deformation coordinated.Furthermore,pyramidal<c+a>slip activation effectively enhances the plasticity of Mg alloys.By post four-pass processing,the alloy exhibits a microhardness of 81.9HV,primarily governed by fine grain strengthening and dislocation strengthening mechanisms.
文摘Industrial robots are integral to modern manufacturing systems,enabling high precision,high throughput,and flexibility.However,errors in accuracy and repeatability,which arise from a variety of sources such as mechanical wear,calibration issues,and environmental factors,can significantly impact the performance of industrial robots.This paper aims to explore the theoretical modeling of errors in industrial robot systems and propose compensation strategies to enhance their accuracy and repeatability.Key factors contributing to errors,such as kinematic,dynamic,and environmental influences,are discussed in detail.Additionally,the paper explores various compensation techniques,including geometric error compensation,dynamic compensation,and adaptive control approaches.Through the integration of error modeling and compensation methods,industrial robots can achieve improved performance,ensuring higher operational efficiency and product quality.The paper concludes by highlighting the challenges and future research directions for improving the accuracy and repeatability of industrial robots in practical applications.
文摘BACKGROUND Repeated application of the Pringle maneuver is a key obstacle to safe minimally invasive repeat liver resection(MISRLR).However,limited technical guidance is available.AIM To study the utility of newly developed Pringle taping method guided by liver surface in MISRLR.METHODS We retrospectively reviewed 72 cases of MISRLR performed by a single surgeon at two centers from August 2015 to July 2024.Beginning in October 2019,a liver surface-guided encirclement of hepatoduodenal ligament(LSEH)was used for repeat Pringle taping.Perioperative outcomes including Pringle taping success,operative time,blood loss,conversion rate,morbidity,and mortality were assessed.RESULTS Laparoscopic and robotic approaches were used in 63 patients and 9 patients,respectively.The median operative time,blood loss,and hospital stay were 331.5 minutes,70 mL,and 8 days,respectively.Open conversion occurred in two cases(2.8%)due to severe adhesions and right renal vein injury.Clavien-Dindo grade≥III complications occurred in 5.6%of cases with no mortality.Anti-adhesion barriers were used in 54 patients(75.0%).LSEH was attempted in 57 cases,improving Pringle taping success from 33.0%to 91.4%(P<0.001).LSEH succeeded in all patients with prior open liver resection(n=11).Among 6 patients in whom LSEH failed,3 patients(50.0%)had undergone a third liver resection,and 1 patient had a history of distal gastrectomy with choledochoduodenostomy.CONCLUSION The newly developed LSEH technique for Pringle taping in MISRLR was feasible,enhancing safety and reproducibility even in patients with a history of open liver resection.
文摘目的:分析江苏省汉族人群亲子鉴定中39个短串联重复序列(short tandem repeat,STR)基因座的突变特征。方法:选取2019年1月—2024年12月南京医科大学第一附属医院司法鉴定所受理的6812例亲子鉴定案例,采用GoldenEye^(TM) DNA身份鉴定系统检测39个STR基因座的突变情况,对突变率、突变来源和步数进行统计分析。结果:在6812例认定亲子关系的案例中,三联体1680例,二联体5132例。共发现214例突变案例,总突变率2.52%。其中,D12S391基因座突变率最高,达0.3297%(28/8492),其次为Penta E、FGA、D21S11、D18S51、D3S1358基因座,突变率均在0.20%以上。突变来源分析中,父源突变189例,母源突变20例,不明原因突变5例,父源突变显著高于母源(P<0.001)。203例(94.86%)突变为一步突变,二步突变9例,FGA和D21S11基因座三步突变各1例。结论:亲子鉴定中39个STR基因座总突变率较高,达2.52%,具有性别和地区差异,在亲子鉴定实践中需加以重视,该结果为江苏地区汉族人群STR基因座突变情况提供数据支撑,有助于提升复杂亲缘关系鉴定的准确性。
基金sponsored by the Special Fund for Earthquake Scientific Research in the Public Welfare of CEA(201308011)
文摘The exciting source of the active source repeated monitoring is located in the Xiliushui Reservoir in Zhangye,Gansu Province. The system began operating normally on July 9,2015,and we had completed a period of 40 days of continuous excitation experiment before November 10,2015. Our results reveal that the airgun source has good consistency and repeatability,and the detective system of active source can record signal clearly. The construction of active source repeated exploration projects has achieved some results,which can provide valuable experience for the research of active source repeated exploration. The observation data we obtained makes it possible to follow the temporal and spatial variations of the deep structure of the Qilian Mountain areas.
基金Funded by the National Natural Science Foundation of China(No.51278073)State Key Laboratoryfor GeoMechanics and Deep Underground Engineering,China University of Mining&Technology(No.SKLGDUEK1704)
文摘The feasibility of using different generations of recycled fine aggregate（RFA） in structural concrete in a chloride environment was evaluated by studying the performance of the RFA and the corresponding concrete. The different generations of RFA were recycled by following the cycle of ‘concrete-waste concrete-fine aggregate-concrete＇. The properties of three generations of repeatedly recycled fine aggregate（RRFA） were systematically investigated, and we focused on the compressive strength and splitting tensile strength and chloride ion permeability of the related structural concretes with 25%, 75%, and 100% replacement of natural fine aggregates with RFA. The results indicated that the quality of RRFA presents a trend of slow deterioration, but the overall performance of all RRFA still fulfils the quality requirements of recycled fine aggregate for structural concrete. All RRFA concretes achieved the target compressive strength of 40 MPa after 28 days except for the second generation of the recycled aggregate concrete and the third generation of the recycled aggregate concrete with 100% replacement, and all the concrete mixes achieved the target compressive strength after 90 days. The insights obtained in this study demonstrate the feasibility of using at least three generations of RRFA for the production of normal structural concrete with a design service life of 100 years in a chloride environment.
基金Project(50504019) supported by the National Natural Science Foundation of ChinaProject(2008BB4040) supported by the Science Foundation of Chongqing, ChinaProject(2008AA4028) supported by Scientific and Technological Project of Chongqing Science and Technology Commission, China
文摘Repeatedly unidirectional bending(RUB) was applied to the magnesium alloy sheet to improve the basal texture.The effect of RUB temperature on resulting structure and room temperature properties was investigated.The texture components of the sheet undergoing RUB at recovery temperature were similar to those of the sheet undergoing RUB at room temperature(RT).As the RUB temperature increased to above recrystallization temperature,the texture components became more disperse and the pyramidal components increased.With the increase of RUB temperature,the grain size near the surface of the sheets undergoing RUB tended to grow up.When the sheets were processed by RUB at medium-high temperature followed by annealing at 533 K,the yield strength and fracture elongation were lower than those of the cold rolled sheet;however,the Erichsen value was slightly higher than that of the cold rolled sheet.The sheet undergoing RUB at RT followed by annealing at 533 K represented the best mechanical properties.
基金funded by Shanghai Municipal Key Task Projects of Prospering Agriculture by Science and Technology Plan in China (Grant No. Hu Nong Ke Gong Zi 2008: 2-1)
文摘Weedy rice exerts a severe impact on rice production by competing for sunlight, water and nutrients. This study assayed the population structure, genetic diversity and origin of Northeast Asia weedy rice by using 48 simple sequence repeat markers. The results showed that weedy rice in Northeast Asia had a high genetic diversity, with Shannon＇s diversity index （I） of 0.748 and the heterozygosity （He） of 0.434. In each regional population, I value varied widely. The widest range of I （0.228-0.489） was observed in the weedy rice of Eastern China, which was larger than that of Northeast China and Korea （0.168-0.270）. The F-statistics of regional populations （Fis, Fit and Fst） also showed higher values in the weedy rice of Eastern China than those of Northeast China and Korea All weedy rice accessions were grouped into two clusters in the unweighted pair group method with arithmetic mean cluster analysis dendrogram, namely Eastern China branch and Northeastern China plus Korea branch. There was significant differentiation in genetic characteristics in weedy rice of northeastern and eastern Asia, especially in Eastern China.
基金supported by the National Natural Science Foundation of China(Grant Nos.52174362 and 51975207)the Natural Science Foundation of Hunan Province(Grant no.2023JJ10020&2021JJ30257)+1 种基金the Xiangtan Special Project for Building a National Innovative City(Grant No.CG-YB20221043)the Yancheng“Talent Plan of Yellow Sea Pearl”for Leading Talent Project.
文摘A new repeated upsetting-extrusion (RUE) process was proposed to improve the microstructure and the mechanical properties of Mg alloys. The effects of deformation temperature on the microstructure and microhardness of RUEed AQ80 Mg alloy were studied. The results showed that Mg alloy is subjected to sufficient corner shear deformation, upsetting deformation, and extrusion deformation, resulting in a large and uniformly distributed effective strain after RUE deformation. The microstructure is refined to an average grain size of 2.1 μm by the continuous dynamic recrystallization (CDRX) mechanism at 250 °C. As the temperature increases to 300 °C, the discontinuous dynamic recrystallization (DDRX) mechanism is activated and the average grain size is refined to 1.6 µm by the combined effect of CDRX and DDRX. In comparison to their parent grains, the orientations of the CDRXed grains show a clearly preferred orientation, but those of the DDRXed grains are completely different. At 350 °C, {10-12} extension twins appear in the microstructure, and the twinning-induced recrystallization (TDRX) mechanism plays an important role in grain refinement. With the two strengthening mechanisms of fine-grained strengthening and dislocation strengthening, the microhardness of the 250 °C sample is greatly improved, with an increase of about 35.1% compared to the initial sample.
基金supported by the National Basic Research Program(973)of China(No.2013CB127700)the Special Fund for Agro-Scientific Research in the Public Interest(No.201303023)+1 种基金the National Natural Science Foundation of China(No.31371882)the 111 Project from the Ministry of Education of China(No.B07049)
文摘Puccinia striiformis f. sp. tritici （Pst） is the obligate biotrophic fungus responsible for stripe rust wheat. In this study, we developed and characterized 20 polymorphic microsatelUte markers from the genomic sequence of an isolate of Chinese Pst race C^32. Polymorphism at each simple sequence repeat （SSR） locus was determined using 32 Pst isolates from 7 countries. The number of alleles varied from 2 to 7 across isolates, and the observed and expected heterozygosities ranged from 0.33 to 0.97 （mean 0.62） and 0.23 to 0.73 （mean 0.51 ）, respectively. As expected the genomic SSR markers were more polymorphic than the expressed sequence tag （EST）-SSR markers developed previously. These markers will be more useful for population genetics and molecular genetics studies in Pst.
基金Portuguese Foundation for Science and Technology(FCT)Project POCTI/CBO/44812/2002+1 种基金Project POCTI/SAU-IMI/56895/2004 National Institutes of Health, R01-CA57362
文摘AIM:To evaluate the influence of MUC1 mucin variable number of tandem repeats (VNTR) variability on H pylori adhesion to gastric cells. METHODS: Enzyme linked immunosorbent assay (ELISA)-based adhesion assays were performed to measure the adhesion of different H pylori strains (HP26695 and HPTx30a) to gastric carcinoma cell lines (GP202 and MKN45) and GP202 clones expressing recombinant MUC1 with different VNTR lengths. RESULTS: Evaluation of adhesion results shows that H pylori pathogenic strain HP26695 has a significantly higher (P < 0.05) adhesion to all the cell lines and clones tested, when compared to the non-pathogenic strain HPTx30a. Bacteria showed a significantly higher (P < 0.05) adhesion to the GP202 cell line, when compared to the MKN45 cell line. Furthermore, both strains showed a significantly higher (P < 0.05) adhesion to GP202 clones with larger MUC1 VNTR domains. CONCLUSION: This work shows that MUC1 mucin variability conditions H pylori binding to gastric cells. The extent of bacterial adhesion depends on the size of theMUC1 VNTR domain. The adhesion is further dependent on bacterial pathogenicity and the gastric cell line. MUC1 mucin variability may contribute to determine H pylori colonization of the gastric mucosa.
基金supported in part by National Natural Science Foundation of China(No.51277106)in part by the National Basic Research Program of China(973 Program)(No.2011CB209405)
文摘Very fast transient over-voltage （VFTO）, induced by disconnector operations in gas- insulated switchgears, has become the limiting dielectric stress at ultra-high voltage levels. Much work has been done to investigate single-strike waveforms of VFTO. However, little study has been carried out investigating the repeated strike process, which would influence VFTO significantly. In this paper, we carried out 450 effective experiments in an ultra-high voltage test circuit, and conducted calculations through the Monte Carlo simulation method, to investigate the repeated strike process. Firstly, the mechanism of the repeated strike process is proposed, based on the ex- perimentai results. Afterwards, statistical breakdown characteristics of disconnectors are obtained and analyzed. Finally, simulations of the repeated strike process are conducted, which indicate that the dielectric strength recovery speed and polarity effect factor have a joint effect on VFTO. This study enhances the understanding of the nature of VFTO, and may help to optimize the disconnector designed to minimize VFTO.
基金funded by the Higher Education Commission(HEC),Government of the Islamic Republic of Pakistan and Edith Cowan University,Perth,Australia。
文摘In the recent past,the potential benefits of wraparound geosynthetic reinforcement technique for constructing the reinforced soil foundations have been reported.This paper presents the experimental study on the behaviour of model strip footing resting on sandy soil bed reinforced with geosynthetic in wraparound and planar forms under monotonic and repeated loadings.The geosynthetic layers were laid according to the reinforcement ratio to minimise the scale effect.It is found that for the same amount of reinforcement material,the wraparound reinforced model resulted in less settlement in comparison to planar reinforced models.The efficiency of wraparound reinforced model increased with the increase in load amplitude and the rate of total cumulative settlement substantially decreased with the increase in number of load cycles.The wraparound reinforced model has shown about 45% lower average total settlement in comparison to unreinforced model,while the double-layer reinforced model has about 41% lower average total settlement at the cost of approximately twice the material and 1.5 times the occupied land width ratio.Moreover,wraparound models have shown much greater stability in comparison to their counterpart models when subjected to incremental repeated loading.
基金Supported by Natural Science Foundation of Guangdong Province of China,No.2017A030313449Science and Technology Planning Project of Guangdong Province of China,No.A2018057。
文摘BACKGROUND Repeated endoscopic probe dilatation is the most preferred treatment for esophageal stenosis which may cause high levels of symptom distress in the patient’s home rehabilitation stage.AIM To explore the changes in the symptom distress level and its correlation with the dilation effect in patients with esophageal carcinoma undergoing repeated dilations for lumen stenosis.METHODS The difference(R2-R1)between the diameter of the esophageal stenosis opening(R1)of the patients before dilation(R1)and after dilation(R2)was calculated to describe the extent and expansion of the esophageal stenosis before and after dilation.The M.D.Anderson Symptom Inventory was used to describe the symptom distress level of patients with dilation intermittence during their stay at home and to explore the correlation between the dilation effect and symptom distress level.RESULTS The diameter of the esophagus(R1)increased before each dilation in patients undergoing esophageal dilation(P<0.05).The diameter(R2)increased after dilation(P<0.05);the dilation effect(R2-R1)decreased with the number of dilations(P<0.05).The total symptom distress score significantly increased with the number of dilations(P<0.05).The symptom distress scores of the patients were negatively correlated(P<0.05)with the previous dilation effect(R2-R1)and the esophageal diameter(R2)after the previous dilation.After the 1 st to 4 th dilations,the patient’s symptom distress score was negatively correlated with the esophageal diameter(R12)before the next dilation,while there was no significant correlation(P>0.05)with the other dilations.CONCLUSION In patients who have undergone repeated dilations,better effect stands for lower symptom distress level and the increase in symptom distress has a prompt effect on the severity of the next occurrence of restenosis.
基金supported by the National Natural Science Foundation of China(Grant Nos.52174362 and 51975207)the Xiangtan Special Project for Building a National Innovative City(Grant No.CG-YB20221043)the Yancheng“Talent Plan of Yellow Sea Pearl"for Leading Talent Project。
文摘In this study, AZ31 Mg alloy was processed by a new severe plasticity deformation methodology with multi-pass lowered temperature, and the deformation behavior and microstructure evolution were investigated by finite element method and electron back-scattered diffraction technique and hardness. The results show that with the increase of deformation pass, the strain gradually springs, and its interval distribution tends to homogenize. Meanwhile, the effective strain increases dramatically with the shear force sudden upgrade in the deformation process. Moreover, the new deformation technique can refine grain size remarkably. With the passes on, {10-12} tensile twins behavior and the pyramidal < c + a > slip are triggered more frequently, leading to the completeness of dynamic recrystallization (DRX) gradually, which weaken and disperse the basal texture obviously. Besides, the standard deviation of hardness is getting smaller, and the maximum can reach 78.40 HV on average, which can be attributed to the even large strain distribution, complete DRX, and the high geometrically necessary dislocation.
基金the National Basic Research Program of China (No.2014CB046905)Innovation Project for Graduates in Jiangsu Province (No.KYLX15_1405)+1 种基金the National Natural Science Foundation of China (Nos.51274191 and 51404245)the Doctoral Fund of Ministry of Education of China (No.20130095110018)
文摘To investigate the abnormal ground pressures and roof control problem in fully mechanized repeated mining of residual coal after room and pillar mining, the roof fracture structural model and mechanical model were developed using numerical simulation and theoretical analysis. The roof fracture characteristics of a repeated mining face were revealed and the ground pressure law and roof supporting condi- tions of the repeated mining face were obtained. The results indicate that when the repeated mining face passes the residual pillars, the sudden instability causes fracturing in the main roof above the old goal and forms an extra-large rock block above the mining face. A relatively stable ＂Voussoir beam＂ structure is formed after the advance fracturing of the main roof. When the repeated mining face passes the old goaf, as the large rock block revolves and touches gangue, the rock block will break secondarily under overburden rock loads. An example calculation was performed involving an integrated mine in Shanxi province, results showed that minimum working resistance values of support determined to be reason- able were respectively 11,412 kN and 10,743 kN when repeated mining face passed through residual pillar and goaf. On-site ground pressure monitoring results indicated that the mechanical model and support resistance calculation were reasonable.
文摘目的通过对236例流产物进行低深度全基因组拷贝数变异检测(copy number variation sequencing,CNV-seq)及短串联重复序列(short tandem repeats,STR)连锁分析检测,探讨其在流产物染色体异常检测中的临床应用价值。方法采用CNV-seq和STR连锁分析对2021年3月-2024年8月于郑州大学第二附属医院产前诊断中心就诊的236例自然流产患者的流产物样本进行检测,确定具有临床意义的染色体异常并对其进行分析。结果6例流产物因严重母源污染退出研究,剩余230例流产物染色体异常的阳性率为62.61%(144/230),其中染色体非整倍体110例(69.44%),多倍体7例(4.86%),拷贝数变异27例(18.75%)。染色体非整倍体中以常染色体三体最为常见,其中16-三体最常见,其次是21-三体。高龄产妇染色体异常率显著高于低龄产妇,早期流产组染色体异常发生率显著高于晚期流产组,均以染色体非整倍体异常为主。结论染色体非整倍体是导致自然流产最常见的原因,孕妇的妊娠年龄与胎儿常染色体三体的发生密切相关。CNV-seq联合STR连锁分析对于流产物的染色体分析高效可靠,可作为流产物遗传学分析的常规方法。
