Bioinformatics Analysis of the Biological Properties of Ewing Sarcoma

Purpose: Bioinformatics-based approach to screen and analyze differentially expressed genes associated with the biological characteristics of Ewing sarcoma. Means: The GSE17674 dataset was selected for analysis, obtained by data retrieval based on the GEO public database. The R language limma toolkit was used to screen DEmRNAs. After the data were normalized, the Metascape online analysis software and the R language clusterProfiler package were used to analyze the GO function and KEGG pathway enrichment of DEmRNAs lines, respectively. The string database was selected for PPI analysis, and the results were imported into Cytoscape software to derive the core modules and predicted core genes. The genes selected above were analyzed for tissue localization specificity. Results: Through the analysis of GSE17674, differentially expressed genes were screened out, and GO and KEGG analyses were performed on the differentially expressed genes. The GO functional enrichment analysis was mainly enriched in the process of muscle system, muscle contraction, myocyte development, contractile fibers, myogenic fibers, myofibers, myofibrillar segments, actin binding, structural composition of muscle, and actin filament binding. KEGG pathway analysis showed that the core pathways associated with the development of ES were the core genes for myocardial contraction, congestive cardiomyopathy, and hypertrophic cardiomyopathy. Five Hub genes were obtained based on Cytoscape prediction. Tissue localization specificity analysis of Hub genes was performed, and a total of 2 Hub genes with tissue specificity were screened;MYH6 was specifically expressed in cardiac cells and MYL1 was specifically expressed in skeletal muscle cells. Conclusions: The differential genes screened will help to understand the molecular mechanisms underlying the highly invasive and metastasis-prone biological characteristics of ES, as well as provide new ideas for clinical drug-targeted treatment of ES.

基于创新人才培养的国家级实验教学示范中心持续建设

化学国家级实验教学示范中心(兰州大学)作为兰州大学“双一流”建设化学学科的重要支撑平台,牢记为党育人初心使命,落实立德树人根本任务,以创新人才培养为目标,搭建出优质的实验教学资源共享平台,形成了“基础→综合→科研训练”三层次的实验教学体系。实验教学改革中强化科教融合、以赛促建,培养学生的创新能力,以高水平实验教学支撑了高质量创新型化学拔尖人才的培养,学生的实践和创新能力增强,综合素质优秀。在课程及教材建设、实验教学改革与研究、实验室建设等方面取得了良好进展,示范辐射作用显著。

“元素无机化学”研究生课程建设及混合式教学实践

为培养高素质研究型创新型人才,对研究生课程“元素无机化学”的课程资源建设和教学模式改革进行了探索与实践。主要举措包括重构分层知识体系、建设多维课程资源、推进线上线下混合式教学、实施全程多维评价、深度融入课程思政。多措并举,提高了学生自主学习、拓展学习、交互学习的能力,实现了“知识传授、能力培养和价值引领浑然一体”的人才培养目标,提升了学生的综合素养和科技创新能力。

近远场地震下RC大跨轻柔拱桥减隔震支座方案优化

为探明不同地震动输入对某大跨轻柔拱桥减隔震的影响,通过非线性有限元模型分析近远场地震下桥梁结构的响应规律,得到大桥支座的优化布置方案.首先,基于模态分析,对比该桥与传统钢筋混凝土(RC)拱桥动力特性差异;其次,选取不同脉冲周期的近场地震动、近场无脉冲及远场长周期地震动记录;最后,研究近远场地震下拱桥的响应行为和损伤演化路径,得到优化桥梁的减隔震支座设计方案.研究结果表明:近场脉冲及远场长周期地震下的桥梁结构响应大于无脉冲地震响应;纵竖向地震下高墩柱剪力及弯矩包络曲线呈“S”形,墩身中部易形成塑性铰,高阶振型影响显著;桥梁纵桥向先于横向震损,损伤路径依次为矮柱、高墩柱及拱肋实心-空心截面段;摩擦摆支座减震效果最佳但位移较大,高阻尼支座方案在近场中长脉冲周期及远场长周期地震下仍会发生损伤,板式橡胶支座方案因无法保证支座同步滑移而不能形成准隔震体系;“高阻尼+摩擦摆”混合方案的支座位移小,拱肋及墩柱均处于弹性,是近断层大跨轻柔RC拱桥的优选减隔震方案.

基于深度学习的学生学习行为规制路径研究

由于自身和外部环境因素的影响,在线上线下混合式教学中,学生会出现一些问题学习行为,而问题学习行为必将弱化学习效果,无法实现深度学习。通过线上线下混合式教学中的学生学习行为,总结教学过程中普遍存在的三个问题:学习目标价值偏离,线上即时引导面临挑战;线下教学模式依赖固化,线上即时指导存在障碍;评价未适用混合式教学,评价结果效用缺位。在此基础上,以规制学生学习行为为目标,提出价值引导、任务驱动及立体评价三个机制。在三个规制机制的指导下,把课程的教学设计作为一种学术研究,在《隧道工程》教学中针对性地创设不同的规制措施,并观测学生的反馈效果。再通过发放问卷调查课程教学的效用,结果表明,该教学设计可以有效增强学生知识习得和优化学习行为,有效促进深度学习的实现。

Lightweight and highly robust memristor-based hybrid neural networks for electroencephalogram signal processing

Memristor-based neuromorphic computing shows great potential for high-speed and high-throughput signal processing applications,such as electroencephalogram(EEG)signal processing.Nonetheless,the size of one-transistor one-resistor(1T1R)memristor arrays is limited by the non-ideality of the devices,which prevents the hardware implementation of large and complex networks.In this work,we propose the depthwise separable convolution and bidirectional gate recurrent unit(DSC-BiGRU)network,a lightweight and highly robust hybrid neural network based on 1T1R arrays that enables efficient processing of EEG signals in the temporal,frequency and spatial domains by hybridizing DSC and BiGRU blocks.The network size is reduced and the network robustness is improved while ensuring the network classification accuracy.In the simulation,the measured non-idealities of the 1T1R array are brought into the network through statistical analysis.Compared with traditional convolutional networks,the network parameters are reduced by 95%and the network classification accuracy is improved by 21%at a 95%array yield rate and 5%tolerable error.This work demonstrates that lightweight and highly robust networks based on memristor arrays hold great promise for applications that rely on low consumption and high efficiency.

一款紧致化妆品的功效评价方法研究

通过对以棕榈酰五肽-4为主要功能成分化妆品的功效进行评价,研究建立人体紧致功效评价方法体系。筛选31名20~50岁女性受试者,分别在使用产品0周、4周和8周,通过客观测试数据、图像方法及受试者自我评估方法对皮肤各项指标进行评估,采集受试者脸颊、眼角部位的皮肤弹性、皮肤真皮密度等参数,以及TPEF图像及SHG图像,并进行比较分析。结果显示,8周后皮肤弹性、真皮密度(P<0.001)及真-表皮链接指数(DEJI)(P<0.01)有显著变化,与受试者自我评分结果一致,表明方法之间具有相关性。该研究方法可为建立化妆品紧致功效评价方法体系提供技术支持。

嗜酸氧化亚铁硫杆菌作用下含黄铁矿废石的生物溶解和动力学

使用生物淋洗处理黄铁矿废石,从源头上缓解其产生酸性矿山废水(AMD)的风险。生物淋洗结果显示,在嗜酸氧化亚铁硫杆菌(A.ferrooxidans)的作用下,40天内可以从黄铁矿废石中去除近82%的铁和硫。动力学研究结果表明,废石中黄铁矿的去除主要受化学反应和内扩散控制。X射线衍射(XRD)和X射线光电子能谱(XPS)的结果表明,在A.ferrooxidans细菌介导下,生物源黄钾铁矾能够钝化废石中残余的黄铁矿。对渣样进行二次生物浸出,试验发现溶液pH没有明显下降,且仅有8 mg/L和160mg/L的铁从两个黄铁矿废石渣样中溶出,表明渣样的酸和铁释放能力得到削弱。

Epidemiological and clinical features,treatment status,and economic burden of traumatic spinal cord injury in China:a hospital-based retrospective study

Traumatic spinal cord injury is potentially catastrophic and can lead to permanent disability or even death.China has the largest population of patients with traumatic spinal cord injury.Previous studies of traumatic spinal cord injury in China have mostly been regional in scope;national-level studies have been rare.To the best of our knowledge,no national-level study of treatment status and economic burden has been performed.This retrospective study aimed to examine the epidemiological and clinical features,treatment status,and economic burden of traumatic spinal cord injury in China at the national level.We included 13,465 traumatic spinal cord injury patients who were injured between January 2013 and December 2018 and treated in 30 hospitals in 11 provinces/municipalities representing all geographical divisions of China.Patient epidemiological and clinical features,treatment status,and total and daily costs were recorded.Trends in the percentage of traumatic spinal cord injuries among all hospitalized patients and among patients hospitalized in the orthopedic department and cost of care were assessed by annual percentage change using the Joinpoint Regression Program.The percentage of traumatic spinal cord injuries among all hospitalized patients and among patients hospitalized in the orthopedic department did not significantly change overall(annual percentage change,-0.5%and 2.1%,respectively).A total of 10,053(74.7%)patients underwent surgery.Only 2.8%of patients who underwent surgery did so within 24 hours of injury.A total of 2005(14.9%)patients were treated with high-dose(≥500 mg)methylprednisolone sodium succinate/methylprednisolone(MPSS/MP);615(4.6%)received it within 8 hours.The total cost for acute traumatic spinal cord injury decreased over the study period(-4.7%),while daily cost did not significantly change(1.0%increase).Our findings indicate that public health initiatives should aim at improving hospitals’ability to complete early surgery within 24 hours,which is associated with improved sensorimotor recovery,increasing the awareness rate of clinical guidelines related to high-dose MPSS/MP to reduce the use of the treatment with insufficient evidence.

Preferentially selective extraction of lithium from spent LiCoO_(2)cathodes by medium-temperature carbon reduction roasting

Lithium recovery from spent lithium-ion batteries(LIBs)have attracted extensive attention due to the skyrocketing price of lithium.The medium-temperature carbon reduction roasting was proposed to preferential selective extraction of lithium from spent Li-CoO_(2)(LCO)cathodes to overcome the incomplete recovery and loss of lithium during the recycling process.The LCO layered structure was destroyed and lithium was completely converted into water-soluble Li2CO_(3)under a suitable temperature to control the reduced state of the cobalt oxide.The Co metal agglomerates generated during medium-temperature carbon reduction roasting were broken by wet grinding and ultrasonic crushing to release the entrained lithium.The results showed that 99.10%of the whole lithium could be recovered as Li2CO_(3)with a purity of 99.55%.This work provided a new perspective on the preferentially selective extraction of lithium from spent lithium batteries.

11.2 W/mm power density AlGaN/GaN high electron-mobility transistors on a GaN substrate

In this letter,high power density AlGaN/GaN high electron-mobility transistors(HEMTs)on a freestanding GaN substrate are reported.An asymmetricΓ-shaped 500-nm gate with a field plate of 650 nm is introduced to improve microwave power performance.The breakdown voltage(BV)is increased to more than 200 V for the fabricated device with gate-to-source and gate-to-drain distances of 1.08 and 2.92μm.A record continuous-wave power density of 11.2 W/mm@10 GHz is realized with a drain bias of 70 V.The maximum oscillation frequency(f_(max))and unity current gain cut-off frequency(f_(t))of the AlGaN/GaN HEMTs exceed 30 and 20 GHz,respectively.The results demonstrate the potential of AlGaN/GaN HEMTs on freestanding GaN substrates for microwave power applications.

高铁桥梁装配式双柱空心墩承插深度研究

高铁桥梁桥墩刚度大,结构及构造有别于公路及市政桥梁,大量既有公路、市政承插式桥墩的研究成果是否适用于承插式铁路墩,需进行深入系统的研究。建立现浇和承插式双柱原型空心墩的非线性有限元模型,并结合既有试验结果验证了建模方法的正确性。通过模拟桥墩在拟静力往复作用下的力学行为,得到双柱空心墩的力-位移曲线,对比承插式桥墩与现浇桥墩滞回性能的差异,结合应变渗透效应及纵筋发展长度确定了承插深度的合理取值范围,并提出最小承插深度计算公式。结果表明:承插式桥墩与现浇墩的承载力差别很小,墩高5 m和10 m时,相差最大为2.8%;承插式桥墩和现浇墩的刚度退化规律基本一致,刚度随着侧向位移的增加而降低,位移较小时刚度退化较快,位移较大时刚度退化减慢;纵筋在塑性铰区及承台顶以下应变渗透区内屈服,在此区域以下400 mm范围应变则迅速减小,应变渗透区段为承插式墩身易损部位;根据本文提出的最小承插深度计算公式得到的高铁空心墩的最小承插深度设计值为0.5D(D为墩柱外径)。为保证承插式桥墩的安全性,应采取合理构造措施确保桥墩应变渗透区段抗震性能,推荐高烈度区桥墩的承插深度大于0.5D。

A Fermi-LAT Study of Globular Cluster Dynamical Evolution in the Milky Way:Millisecond Pulsars as the Probe

Using archival Fermi-LAT data with a time span of~12 yr,we study the population of Millisecond Pulsars(MSPs)in Globular Clusters(GlCs)and investigate their dependence on cluster dynamical evolution in the Milky Way.We show that theγ-ray luminosity(L_(γ))and emissivity(i.e.,ε_(γ)=L_(γ)/M,with M the cluster mass)are good indicators of the population and abundance of MSPs in GlCs,and they are highly dependent on the dynamical evolution history of the host clusters.Specifically speaking,the dynamically older GlCs with more compact structures are more likely to have larger L_(γ)andε_(γ),and these trends can be summarized as strong correlations with cluster stellar encounter rateΓand the specific encounter rate(Λ=Γ/M),with L_(γ)∝Γ^(0.7±0.11)andε_(γ)∝Λ^(0.73±0.13)for dynamically normal GlCs.However,as GlCs evolve into deep core collapse,these trends are found to be reversed,implying that strong encounters may have lead to the disruption of Low-Mass X-ray Binaries and ejection of MSPs from core-collapsed systems.Besides,the GlCs are found to exhibit largerε_(γ)with increasing stellar mass function slope(ε_(γ)∝10^((0.52±0.1)α)),decreasing tidal radius(ε_(γ)∝R_(t)^(-10±0.22))and distances from the Galactic Center(GC,ε_(γ)∝R_(gc)^(-1.13±0.21)).These correlations indicate that,as GlCs losing kinetic energy and spiral in toward the GC,tidal stripping and mass segregation have a preference in leading to the loss of normal stars from GlCs,while MSPs are more likely to concentrate to cluster center and be deposited into the GC.Moreover,we gaugeε_(γ)of GlCs is~10-1000 times larger than the Galactic bulge,the latter is thought to reside thousands of unresolved MSPs and may be responsible for the GC 7-ray excess,which supports that GlCs are generous contributors to the population of MSPs in the GC.

Identification and distribution of 13003 landslides in the northwest margin of Qinghai-Tibet Plateau based on human-computer interaction remote sensing interpretation

The periphery of the Qinghai-Tibet Plateau is renowned for its susceptibility to landslides.However,the northwestern margin of this region,characterised by limited human activities and challenging transportation,remains insufficiently explored concerning landslide occurrence and dispersion.With the planning and construction of the Xinjiang-Tibet Railway,a comprehensive investigation into disastrous landslides in this area is essential for effective disaster preparedness and mitigation strategies.By using the human-computer interaction interpretation approach,the authors established a landslide database encompassing 13003 landslides,collectively spanning an area of 3351.24 km^(2)(36°N-40°N,73°E-78°E).The database incorporates diverse topographical and environmental parameters,including regional elevation,slope angle,slope aspect,distance to faults,distance to roads,distance to rivers,annual precipitation,and stratum.The statistical characteristics of number and area of landslides,landslide number density(LND),and landslide area percentage(LAP)are analyzed.The authors found that a predominant concentration of landslide origins within high slope angle regions,with the highest incidence observed in intervals characterised by average slopes of 20°to 30°,maximum slope angle above 80°,along with orientations towards the north(N),northeast(NE),and southwest(SW).Additionally,elevations above 4.5 km,distance to rivers below 1 km,rainfall between 20-30 mm and 30-40 mm emerge as particularly susceptible to landslide development.The study area’s geological composition primarily comprises Mesozoic and Upper Paleozoic outcrops.Both fault and human engineering activities have different degrees of influence on landslide development.Furthermore,the significance of the landslide database,the relationship between landslide distribution and environmental factors,and the geometric and morphological characteristics of landslides are discussed.The landslide H/L ratios in the study area are mainly concentrated between 0.4 and 0.64.It means the landslides mobility in the region is relatively low,and the authors speculate that landslides in this region more possibly triggered by earthquakes or located in meizoseismal area.

Close Major-merger Pairs at z=0: Star-forming Galaxies with Pseudobulges

We present a study of star-forming galaxies (SFGs) with pseudobulges (bulges with Sérsic index n<2) in a loca close major-merger galaxy pair sample (H-KPAIR).With data from new aperture photometries in the optical and near-infrared bands (aperture size of 7 kpc) and from the literature,we find that the mean Age of central stellar populations in Spirals with pseudobulges is consistent with that of disky galaxies and is nearly constant against the bulge-to-total ratio (B/T).Paired Spirals have a slightly lower fraction of pure disk galaxies (B/T≤0.1) than their counterparts in the control sample.Compared to SFGs with classical bulges,those with pseudobulges have a higher (>2σ) mean of specific star formation rate (sSFR) enhancement (sSFR_(enh)=0.33±0.07 versus sSFR_(enh)=0.12±0.06) and broader scatter (by~1 dex).The eight SFGs that have the highest sSFR_(enh)in the sample all have pseudobulges.A majority (69%) of paired SFGs with strong enhancement (having sSFR more than5 times the median of the control galaxies) have pseudobulges.The Spitzer data show that the pseudobulges in these galaxies are tightly linked to nuclear/circum-nuclear starbursts.Pseudobulge SFGs in S+S and in S+E pairs have significantly (>3σ) different sSFR enhancement,with the means of sSFR_(enh)=0.45±0.08 and-0.04±0.11respectively.We find a decrease in the sSFR enhancements with the density of the environment for SFGs with pseudobulges.Since a high fraction (5/11) of pseudobulge SFGs in S+E pairs are in rich groups/clusters (loca density N_(1Mpc)≥7),the dense environment might be the cause for their low s SFR_(enh).

Command filtered integrated estimation guidance and control for strapdown missiles with circular field of view

In this paper,an integrated estimation guidance and control(IEGC)system is designed based on the command filtered backstepping approach for circular field-of-view(FOV)strapdown missiles.The threedimensional integrated estimation guidance and control nonlinear model with limited actuator deflection angle is established considering the seeker's FOV constraint.The boundary time-varying integral barrier Lyapunov function(IBLF)is employed in backstepping design to constrain the body line-of-sight(BLOS)in IEGC system to fit a circular FOV.Then,the nonlinear adaptive controller is designed to estimate the changing aerodynamic parameters.The generalized extended state observer(GESO)is designed to estimate the acceleration of the maneuvering targets and the unmatched time-varying disturbances for improving tracking accuracy.Furthermore,the command filters are used to solve the"differential expansion"problem during the backstepping design.The Lyapunov theory is used to prove the stability of the overall closed-loop IEGC system.Finally,the simulation results validate the integrated system's effectiveness,achieving high accuracy strikes against maneuvering targets.

Resistance development,cross-resistance,and fitness costs associated with Aphis gossypii resistance towards sulfoxaflor and acetamiprid in different geographical regions

Aphis gossypii has become increasingly difficult to manage due to its strong insecticide resistance.In the laboratory,we established sulfoxaflor-resistant and acetamiprid-resistant strains in two A.gossypii populations with different basal insecticide resistance levels,and evaluated the effects of basal insecticide resistance on the resistance development and cross-resistance,as well as differences in fitness.Under the same selection pressure,Yarkant A.gossypii(with low basal insecticide resistance)evolved resistance to sulfoxaflor and acetamiprid more quickly than Jinghe A.gossypii(with high basal insecticide resistance),and the evolution of A.gossypii resistance to sulfoxaflor developed faster than acetamiprid in both Yarkant and Jinghe,Xingjiang,China.The sulfoxaflor-resistant strains selected from Yarkant and Jinghe developed significant cross-resistance to acetamiprid,imidacloprid,thiamethoxam and pymetrozine;while the acetamiprid-resistant strains developed significant cross-resistance to sulfoxaflor,imidacloprid,thiamethoxam,pymetrozine,and chlorpyrifos.The relative fitness of A.gossypii decreased as the resistance to sulfoxaflor and acetamiprid developed.The relative fitness levels of the sulfoxaflor-resistant strains(Yarkant-SulR and Jinghe-SulR)were lower than those of the acetamipridresistant strains(Yarkant-AceR and Jinghe-AceR).In addition,the relative fitness levels of sulfoxaflor-and acetamiprid-resistant strains were lower in Jinghe than in Yarkant.In summary,basal insecticide resistance of A.gossypii and insecticide type affected the evolution of resistance to insecticides in A.gossypii,as well as cross-resistance to other insecticides.The sulfoxaflor-and acetamiprid-resistant A.gossypii strains had obvious fitness costs.The results of this work will contribute to the insecticide resistance management and integrated management of A.gossypii.

Rapid discovery of a novel “green” and natural GST inhibitor for sensitizing hepatocellular carcinoma to Cisplatin by visual screening strategy

Over-expression of glutathione S-transferase(GST)can promote Cisplatin resistance in hepatocellular carcinoma(HCC)treatment.Hence,inhibiting GST is an attractive strategy to improve Cisplatin sensitivity in HCC therapy.Although several synthesized GST inhibitors have been developed,the side effects and narrow spectrum for anticancer seriously limit their clinical application.Considering the abundance of natural compounds with anticancer activity,this study developed a rapid fluorescence technique to screen“green”natural GST inhibitors with high specificity.The fluorescence assay demonstrated that schisanlactone B(hereafter abbreviated as C1)isolated from Xue tong significantly down-regulated GST levels in Cisplatin-resistant HCC cells in vitro and in vivo.Importantly,C1 can selectively kill HCC cells from normal liver cells,effectively improving the therapeutic effect of Cisplatin on HCC mice by downregulating GST expression.Considering the high GST levels in HCC patients,this compound demonstrated the high potential for sensitizing HCC therapy in clinical practice by down-regulating GST levels.

Microdynamic mechanical properties and fracture evolution mechanism of monzogabbro with a true triaxial multilevel disturbance method

The far-field microdynamic disturbance caused by the excavation of deep mineral resources and underground engineering can induce surrounding rock damage in high-stress conditions and even lead to disasters.However,the mechanical properties and damage/fracture evolution mechanisms of deep rock induced by microdynamic disturbance under three-dimensional stress states are unclear.Therefore,a true triaxial multilevel disturbance test method is proposed,which can completely simulate natural geostress,excavation stress redistribution(such as stress unloading,concentration and rotation),and subsequently the microdynamic disturbance triggering damaged rock failure.Based on a dynamic true triaxial test platform,true triaxial microdynamic disturbance tests under different frequency and amplitudes were carried out on monzogabbro.The results show that increasing amplitude or decreasing frequency diminishes the failure strength of monzogabbro.Deformation modulus gradually decreases during disturbance failure.As frequency and amplitude increase,the degradation rate of deformation modulus decreases slightly,disturbance dissipated energy increases significantly,and disturbance deformation anisotropy strengthens obviously.A damage model has been proposed to quantitatively characterize the disturbance-induced damage evolution at different frequency and amplitude under true triaxial stress.Before disturbance failure,the micro-tensile crack mechanism is dominant,and the micro-shear crack mechanism increases significantly at failure.With the increase of amplitude and frequency,the micro-shear crack mechanism increases.When approaching disturbance failure,the acoustic emission fractal dimension changes from a stable value to local large oscillation,and finally increases sharply to a high value at failure.Finally,the disturbance-induced failure mechanism of surrounding rock in deep engineering is clearly elucidated.

The role of cAMP-dependent protein kinase A in the formation of long-term memory in Bactrocera dorsalis

The cAMP-dependent protein kinase A(PKA)signaling pathway has long been considered critical for long-term memory(LTM)formation.Previous studies have mostly focused on the role of PKA signaling in LTM induction by multiple spaced conditioning with less attention to LTM induction by a single conditioning.Here,we conducted behavioral-pharmacology,enzyme immunoassay and RNA interference experiments to study the role of the PKA signaling pathway in LTM formation in the agricultural pest Bactrocera dorsalis,which has a strong memory capacity allowing it to form a two-day memory even from a single conditioning trial.We found that either blocking or activating PKA prior to conditioning pretreatment affected multiple spaced LTM,and conversely,they did not affect LTM formed by single conditioning.This was further confirmed by enzyme-linked immunosorbent assay(ELISA)and silencing of the protein kinase regulatory subunit 2 and catalytic subunit 1.Taken together,these results suggest that activating PKA during memory acquisition helps to induce the LTM formed by multiple spaced conditioning but not by a single conditioning.Our findings challenge the conserved role of PKA signaling in LTM,which provides a basis for the greater diversity of molecular mechanisms underlying LTM formation across species,as well as possible functional and evolutionary implications.