Impacts of high temperature,relative air humidity,and vapor pressure deficit on the seed set of contrasting maize genotypes during flowering

Heat stress is a major constraint to current and future maize production at the global scale.Male and female reproductive organs both play major roles in increasing seed set under heat stress at flowering,but their relative contributions to seed set are unclear.In this study,a 2-year field experiment including three sowing dates in each year and 20 inbred lines was conducted.Seed set,kernel number per ear,and grain yield were all reduced by more than 80%in the third sowing dates compared to the first sowing dates.Pollen viability,silk emergence ratio,and anthesis-silking interval were the key determinants of seed set under heat stress;and their correlation coefficients were 0.89^(***),0.65^(***),and-0.72^(***),respectively.Vapor pressure deficit(VPD)and relative air humidity(RH)both had significant correlations with pollen viability and the silk emergence ratio.High RH can alleviate the impacts of heat on maize seed set by maintaining high pollen viability and a high silk emergence ratio.Under a warming climate from 2020 to 2050,VPD will decrease due to the increased RH.Based on their pollen viability and silk emergence ratios,the 20 genotypes fell into four different groups.The group with high pollen viability and a high silk emergence ratio performed better under heat stress,and their performance can be further improved by combining the improved flowering pattern traits.

Fine-grained grid computing model for Wi-Fi indoor localization in complex environments

The fingerprinting-based approach using the wireless local area network(WLAN)is widely used for indoor localization.However,the construction of the fingerprint database is quite time-consuming.Especially when the position of the access point(AP)or wall changes,updating the fingerprint database in real-time is difficult.An appropriate indoor localization approach,which has a low implementation cost,excellent real-time performance,and high localization accuracy and fully considers complex indoor environment factors,is preferred in location-based services(LBSs)applications.In this paper,we proposed a fine-grained grid computing(FGGC)model to achieve decimeter-level localization accuracy.Reference points(RPs)are generated in the grid by the FGGC model.Then,the received signal strength(RSS)values at each RP are calculated with the attenuation factors,such as the frequency band,three-dimensional propagation distance,and walls in complex environments.As a result,the fingerprint database can be established automatically without manual measurement,and the efficiency and cost that the FGGC model takes for the fingerprint database are superior to previous methods.The proposed indoor localization approach,which estimates the position step by step from the approximate grid location to the fine-grained location,can achieve higher real-time performance and localization accuracy simultaneously.The mean error of the proposed model is 0.36 m,far lower than that of previous approaches.Thus,the proposed model is feasible to improve the efficiency and accuracy of Wi-Fi indoor localization.It also shows high-accuracy performance with a fast running speed even under a large-size grid.The results indicate that the proposed method can also be suitable for precise marketing,indoor navigation,and emergency rescue.

The circular RNA Rap1b promotes Hoxa5 transcription by recruiting Kat7 and leading to increased Fam3a expression,which inhibits neuronal apoptosis in acute ischemic stroke

Circular RNAs can regulate the development and progression of ischemic cerebral disease.However,it remains unclear whether they play a role in acute ischemic stroke.To investigate the role of the circular RNA Rap1b(circRap1b)in acute ischemic stroke,in this study we established an in vitro model of acute ischemia and hypoxia by subjecting HT22 cells to oxygen and glucose deprivation and a mouse model of acute ischemia and hypoxia by occluding the right carotid artery.We found that circRap1b expression was remarkably down-regulated in the hippocampal tissue of the mouse model and in the HT22 cell model.In addition,Hoxa5 expression was strongly up-regulated in response to circRap1b overexpression.Hoxa5 expression was low in the hippocampus of a mouse model of acute ischemia and in HT22-AIS cells,and inhibited HT22-AIS cell apoptosis.Importantly,we found that circRap1b promoted Hoxa5 transcription by recruiting the acetyltransferase Kat7 to induce H3K14ac modification in the Hoxa5 promoter region.Hoxa5 regulated neuronal apoptosis by activating transcription of Fam3a,a neuronal apoptosis-related protein.These results suggest that circRap1b regulates Hoxa5 transcription and expression,and subsequently Fam3a expression,ultimately inhibiting cell apoptosis.Lastly,we explored the potential clinical relevance of circRap1b and Hoxa5 in vivo.Taken together,these findings demonstrate the mechanism by which circRap1b inhibits neuronal apoptosis in acute ischemic stroke.

小模数塑料齿轮静态强度试验台研制与实验研究

为获取小模数塑料齿轮的静态强度,研发了小模数塑料齿轮静态强度试验台,可以精准测量出不同模数、转速、材料的塑料齿轮的静态强度。重点介绍了试验台的工作原理、构成和工装零部件的设计。试验台由机械系统、电控系统和测量软件组成,主要采用卧式结构,结构紧凑,占用空间小,工装夹具设计简单,便于测量。进行了静态强度的测试试验,测试了不同材料的静态强度。该试验台的研发,解决了小模数齿轮静态强度测试不准、测试装夹困难的问题。研究对塑料齿轮设计有一定的理论价值与实际应用价值。

Graphene quantum dots as sulfiphilic and lithiophilic mediator toward high stability and durable life lithium-sulfur batteries

The development of lithium-sulfur(Li-S) battery as one of the most attractive energy storage systems among lithium metal batteries is seriously hindered by low sulfur utilization, poor cycle stability and uneven redeposition of Li anode. It is necessary to propose strategies to address the problems as well as improve the electrochemical performance. One of the effective solutions is to improve the sulfiphilicity of sulfur cathode and the lithiophilicity of the Li anode. Herein, we reported that a synergistic functional separator(graphene quantum dots(GQDs)-polyacrylonitrile(PAN) @polypropylene(PP) separator)improved the electrochemical activity of sulfur cathode as well as the stability of Li anode. GQDs induced uniform Li^(+)nucleation and deposition, which slowed down the passivation of Li anode and avoided shortcircuit. Further, three-dimensional network constructed by electrospinning nanofibers and the polar functional groups of GQDs could both effectively inhibit the shuttle of LiPSs and improve the sulfur utilization. The stability of Li-S battery was improved by the synergistic effect. In addition, GQDs and electrospinning nanofibers protector increased lifetime of separators. Benefiting from the unique design strategy, Li//Li symmetric battery with GQDs-PAN@PP separators exhibited stably cycling for over 600 h. More importantly, the Li-S full batteries based GQDs-PAN@PP separators enabled high stability and desirable sulfur electrochemistry, including high reversibility of 558.09 mA h g^(-1)for 200 cycles and durable life with a low fading rate of 0.075% per cycle after 500 cycles at 0.5 C. Moreover, an impressive areal capacity of 3.23 mA h cm^(-2)was maintained under high sulfur loading of 5.10 mg cm^(-2). This work provides a new insight for modification separator to improve the electrochemical performance of Li-S/Li metal batteries.

Single-cell sequencing analysis reveals the molecular mechanism of promotion of SCAP proliferation upon AZD2858 treatment

The Wnt/β-catenin signaling pathway is the main target of tooth regeneration regulation.Treatment of cells with AZD2858 stimulates the Wnt/β-catenin signaling pathway,yet the function of this pathway in tooth regeneration remains unclear.Here,we found that AZD2858 promotes the accumulation ofβ-catenin in the nuclei of stem cells from the apical papilla(SCAPs)and enhances cell proliferation.Single-cell sequencing was performed on SCAPs treated with AZD2858.Eight clusters were identified,namely SCAPs-CNTNAP2,SCAPs-DTL,SCAPs-MYH11,SCAPs-MKI67,SCAPs-CXCL8,SCAPs-TPM2,SCAPs-IFIT2 and SCAPs-NEK10.The pseudo-time trajectory analysis showed that AZD2858 enhanced the evolution of SCAPs from SCAPs-TMP2 clusters to SCAPs-MYH11,SCAPs-CNTNAPs and SCAPs-NEK10 clusters via up-regulation of PRKCA,SMURF2,MAGI2,RBMS3,EXT1,CAMK2D,PLCB4,and PLCB1.These results demonstrate that AZD2858 enhances the proliferation of SCAPs-TPM2 cluster by activating the non-canonical Wnt/β-catenin signaling pathway.

Applying the Kalman filter particle method to strange and open charm hadron reconstruction in the STAR experiment

We applied KF Particle, a Kalman Filter package for secondary vertex finding and fitting, to strange and open charm hadron reconstruction in heavy-ion collisions in the STAR experiment. Compared to the conventional helix swimming method used in STAR, the KF Particle method considerably improved the reconstructed Λ, Ω, and D~0 significance. In addition, the Monte Carlo simulation with STAR detector responses could adequately reproduce the topological variable distributions reconstructed in real data using the KF Particle method, thereby retaining substantial control of the reconstruction efficiency uncertainties for strange and open charm hadron measurements in heavy-ion collisions.

Prognostic role of ring finger and WD repeat domain 3 and immune cell infiltration in hepatocellular carcinoma

We have found that the expression of ring finger and WD repeat domain 3(RFWD3)is significantly higher in unpaired and paired hepatocellular carcinoma(HCC)tissues than in normal tissues.Moreover,this expression has a significant correlation with the infiltration level of 14 immune cell types and when the detected RFWD3 expression levels were grouped as high and low,a prominent difference was revealed for overall survival,disease-specific survival,and progression-free interval.Through statistical analysis(univariate Cox),we were also able to identify RFWD3 as an independent prognostic element for HCC,with RFWD3 having an ability to accurately predict HCC prognosis(area under the curve of 0.863).Finally,we have generated prognostic nomograms for probabilities of 1-,3-and 5-year overall survival in HCC via integrating the factors of age,pathologic stage,alpha-fetoprotein level,and RFWD3 expression.

船用中速柴油机高压共轨燃油系统特性分析

为开展船用柴油机机械式喷油系统向高压共轨式喷油系统的改造研究,以船用中速柴油机为研究对象,建立了原机机械式燃油喷射系统仿真模型,在分析机械喷射系统性能的基础上,设计了额定工况轨压为160 MPa的“分段式”高压共轨燃油喷射系统.通过建立的高压共轨燃油喷射系统仿真建模,分析了高压共轨燃油喷射系统的性能特征,研究了系统部件关键结构参数对系统特性的影响.

Study on Landscape Pattern Based on Landsat-8 in the Center of Chengdu City, China

Study on landscape spatial pattern in the center of Chengdu City is based on the Landsat-8 image by using 3S technique and spatial pattern analysis software Fragstats 3.3. The results showed that there covered an area of 193.92 km2 in the center of Chengdu City. 55.24% of the total area was made up of buildings, covering an area of 107.12 km2, and the overall landscape of impervious ground-based. There were 22,666 patches;29.67% of the patches were roads. The human interference of buildings, roads and green space was a maximum;fragmentation of the highest was green space. The fragmentation of overall urban landscape was high;the diversity was low;the value of Shannon’s diversity index was 0.63;the value of Shannon’s evenness index was 0.70. All kinds of landscape distribution were not balanced, and lack of connectivity. This research puts important reference for creating good urban landscape space and restoring the natural ecological environment in the western regions of China.

微小型行星减速器强度性能试验台的研制

为研究微小型行星减速器的强度性能,研制了微小型行星减速器强度性能试验台,可准确地测量出断裂破坏实验中减速器齿轮承载力矩和转角的关系。试验台由机械系统、测控系统和测量软件构成,主机采用立式结构,结构简单,装卡方便,便于操作。重点介绍了试验台的工作原理、构成和主要零部件的设计。试验结果表明,该试验台可以实现微小型行星减速器齿轮强度性能的快速测量,为测量结果的统计分析和改进微小型减速器的设计提供了依据。

塑料齿轮缩腰的机理分析及解决方法

以某塑料齿轮为例,利用Moldflow分析塑料齿轮产生缩腰的机理,提出采用鼓形电极加工模具型腔板以消除塑料齿轮缩腰的现象,并详细介绍了塑料齿轮的成型方法,实际生产表明该方法有效解决了塑料齿轮成型中的缩腰问题。

左心瓣膜疾病相关性肺动脉高压的临床分析

目的观察和分析左心瓣膜疾病相关性肺高压(pulmonary artery hypertension due to left heart valve diseases,LHD-PAH)的临床特征、危险因素和对临床结局的影响。方法纳入2012年1月至2015年2 月在我科行体外循环心脏瓣膜手术的患者。以超声心动图为主要诊断标准,LHD-PAH采用三尖瓣反流法估算的肺动脉收缩压值进行诊断。收集患者的临床信息进行统计分析。结果共纳入958例患者,其中合并LHD-PAH的患者共391例,占40.8%。通过单因素分析及多因素Logistic回归分析,我们发现射血分数<30%(OR=4.490,95%CI 1.920-10.499,P<0.01)、心房颤动(OR=9.654,95%CI 3.214-21.411 ,P<0.01)、左心房血栓(OR=3.991,95%CI 2.946-5.406,P<0.01)为LHD-PAH的独立危险因素。一旦左心瓣膜疾病患者出现 LHD-PAH后,其体外循环转流时间将会显著高于非LHD-PAH患者(P<0.01),然而主动脉阻断时间则无显著差异(P=0.331)o而且,LHD-PAH的出现还会增加患者的机械通气时间、ICU留治时间、总住院日以及病死率(P<0.01)。结论LHD-PAH在临床中发生率较高,患者临床结局不良,射血分数<30%、心房颤动和左心房血栓是其独立危险因素。

Comparative analysis of essential oils found in Rhizomes Curcumae and Radix Curcumae by gas chromatography-mass spectrometry

A comparison of the volatile compounds in Rhizomes Curcumae （Ezhu） and Radix Curcumae （Yujin） was undertaken using gas chromatography mass spectrometi-y （GC-MS）. Ultrasonic extraction and GC-MS methods were developed for the simultaneous determination of five sesquiterpenes, namely, α-pinene, β-elemene, curcumol, germacrone and curdione, in Ezhu and Yunjin. Good linearity （r〉0.999） and high inter-day precision were observed over the investigated concentration ranges. The validated method was successfully used for the simultaneous determination of five sesquiterpenes in Ezhu and Yujin. The quantitative method can be effectively used to evaluate and monitor the quality of Chinese curcuma in clinical use.

UPLC-Q-TOF/MS based metabolomic profiling of serum and urine of hyperlipidemic rats induced by high fat diet

Hyperlipidemia is considered to be a high lipid level in blood,can induce metabolic disorders and dysfunctions of the body,and results in some severe complications.Therefore,hunting for some metabolite markers and clarifying the metabolic pathways in vivo will be an important strategy in the treatment and prevention of hyperlipidemia.In this study,a rat model of hyperlipidemia was constructed according to histopathological data and biochemical parameters,and the metabolites of serum and urine were analyzed by UPLC-Q-TOF/MS.Combining pattern recognition and statistical analysis.19 candidate biomarkers were screened and identified.These changed metabolites indicated that during the development and progression of hyperlipidemia,energy metabolism,lipid metabolism,amino acid metabolism and nucleotide metabolism were mainly disturbed,which are reported to be closely related to diabetes,cardiovascular diseases,etc.This study demonstrated that a UPLC-Q-TOF/MS based metabolomic approach is useful to profile the alternation of endogenous metabolites of hyperlipidemia.

树脂乳液研究的回顾和应用于油田堵水的思考

综述热固性树脂乳化方法的研究进展以及树脂乳液的特性,介绍油田应用的选择性堵水剂和非选择性堵水剂的研究进展,并且分析了常用堵水剂的优缺点和应用效果。最后,对热固性树脂乳液体系在油田堵水方面的应用进行了分析。

Using cell membrane chromatography and HPLC-TOF/MS method for in vivo study of active components from roots of Aconitum carmichaeli

An offline two-dimensional system combining a rat cardiac mascle cell membrane chromatography time-of-flight mass spectrometry （CMC-TOF/MS） with a high performance liquid chromatography time-of-flight mass spectrometry （HPLC-TOF/MS） was established for investigating the parent components and metabolites in rat urine samples after administration of the roots of Aconitum carmichaeli. On the basis of the analysis of the first dimension, retention components of the urine sample were collected into 30 fractions （one fraction per minute）. Then offline analysis of the second dimension was carried out. 34 compounds including 24 parent alkaloids and 10 potential metabolites were identified from the dosed rat urine, and then binding affinities of different compounds on cell membranes were compared and influences of some functional groups on activity were estimated with the semi-quantification and curve fitting method. As a result, binding affinities decreased along with the process of deacylation, debenzoylation and demethylation, which may be related to the alleviation of toxicity in the procedure of herb processing or metabolism. Moreover, some minor components in rat urine （Songorine, 14-benzoylneoline, Deoxyaconitine, etc. ） exerted relatively strong affinity on cell membranes are worth exploring. The results delivered by the system suggest that the CMC can be applied to in vivo study.

Development of high-oil maize haploid inducer with a novel phenotyping strategy

Doubled haploid(DH) technology is important in modern maize breeding. Haploid inducers determine the efficiency of both haploid induction and identification. It has taken decades to improve the efficiency,haploid induction rate(HIR), from the ~2% of the ancestor haploid inducer, stock6, to the ~10% of modern haploid inducers. Improvement of kernel oil content(KOC) would further enhance haploid identification efficiency. Using molecular marker-assisted selection, in combine with the number of haploids per ear as phenotypic criterion, we developed a new high-oil haploid inducer line, CHOI4, with a mean HIR of 15.8%and mean KOC of 11%. High KOC of CHOI4 can achieve a mean accuracy greater than 90% in identification of haploids of different backgrounds, with reduced false discovery rates and false negative rates in comparison with the previous high-oil haploid inducer line, CHOI3. Comparison of phenotypic selection strategies suggested that the number of haploids per ear can be used as a phenotyping criterion during haploid inducer line development. CHOI4 could further increase the efficiency of large-scale DH breeding programs with lower cost.

Temperature-dependent photoluminescence on organic inorganic metal halide perovskite CH_3NH_3Pb I_(3-)Cl_ prepared on ZnO/FTO substrates using a two-step method

Temperature-dependent photoluminescence characteristics of organic-inorganic halide perovskite CH3NH3Pb I3-xClx films prepared using a two-step method on ZnO/FTO substrates were investigated. Surface morphology and absorption characteristics of the films were also studied. Scanning electron microscopy revealed large crystals and substrate coverage. The orthorhombic-to-tetragonal phase transition temperature was-140 K. The films＇ exciton binding energy was 77.6 ± 10.9 meV and the energy of optical phonons was 38.8 ± 2.5 meV. These results suggest that perovskite CH3NH3Pb I（3-x）Clx films have excellent optoelectronic characteristics which further suggests their potential usage in perovskitebased optoelectronic devices.

浇口对玻纤增强塑料齿轮精度及力学性能的影响

通过对3点进料玻纤增强塑料齿轮的齿形精度及力学性能进行测试,结合MoldFlow模拟仿真结果,分析了齿轮啮合精度低、齿轮强度一致性差的原因。针对此问题,提出采用中心进料的设计方案,实现了玻纤的均匀排列,结果证明该方法可有效提高玻纤增强塑料齿轮的啮合精度和齿轮强度的一致性。