Treatment of Synovial Cysts in Relation to the Tibial Tunnel of Anterior Cruciate Ligament Grafts by Filling the Tunnel with Acrylic Cement

Introduction: Synovial cyst of the tibial tunnel in connection with anterior cruciate ligament (ACL) reconstruction is a rare but particularly troublesome complication. Medical treatment is often doomed to failure, and surgical treatment usually consists of excising the cyst and filling the tunnel with bone. The aim of this study was to evaluate the results of filling the tunnel with acrylic cement. Hypothesis: Filling the tibial bone tunnel with acrylic cement should eliminate communication between the joint cavity and the pre-tibial surface and prevent cyst recurrence. Patients and Methods: This retrospective series is composed of 13 patients, 9 men and 4 women, mean age 48.5 years (31 to 64) operated on between 2011 and 2019 for an intra- and extraosseous synovial cyst consecutive to the tibial tunnel of an ACL graft. Between 1983 and 2016, 12 of the patients had had a bone graft without bone block fixation (DI-DT or Mac Intosh) and one patient, a bone-bone transplant (KJ). The cyst was of variable size, located on the anteromedial aspect of the proximal end of the tibia, and often painful, warranting consultation. At the time of the initial operation, 9 patients had undergone meniscectomies (6 medial, 2 lateral, 1 double). In 7 knees, there were 7 cartilage lesions in the femorotibial and/or patellofemoral compartments (one stage 1 lesion, 2 stage 2 lesions, 4 stage 3 lesions, and no stage 4 lesions). Only 2 knees had neither cartilage nor meniscus lesions. After curettage of the bone tunnel /− removal of the non-resorbed or PEEK interference screw, the tunnel was filled with acrylic cement /− reinforced with a ligament staple to prevent expulsion. All patients underwent regular follow-up consultations until recovery. Results: At a maximum follow-up of 8 years, only 1 cyst recurred, representing a 7.69% failure rate. It was reoperated with another technique, which involved filling the tibial bone tunnel with bone graft taken from a half-bank head. After recovery, the cyst healed definitively. All patients were able to return to their previous activity within 15 days of surgery. Conclusion: Filling the tibial tunnel with acrylic cement reinforced /− with a ligament staple is a reliable and rapid solution for the treatment of intra- and extra-articular synovial cysts in relation to the tibial tunnel of ACL grafts.

Heterogeneous information phase space reconstruction and stability prediction of filling body–surrounding rock combination

Traditional research believes that the filling body can effectively control stress concentration while ignoring the problems of unknown stability and the complex and changeable stress distribution of the filling body–surrounding rock combination under high-stress conditions.Current monitoring data processing methods cannot fully consider the complexity of monitoring objects,the diversity of monitoring methods,and the dynamics of monitoring data.To solve this problem,this paper proposes a phase space reconstruction and stability prediction method to process heterogeneous information of backfill–surrounding rock combinations.The three-dimensional monitoring system of a large-area filling body–surrounding rock combination in Longshou Mine was constructed by using drilling stress,multipoint displacement meter,and inclinometer.Varied information,such as the stress and displacement of the filling body–surrounding rock combination,was continuously obtained.Combined with the average mutual information method and the false nearest neighbor point method,the phase space of the heterogeneous information of the filling body–surrounding rock combination was then constructed.In this paper,the distance between the phase point and its nearest point was used as the index evaluation distance to evaluate the stability of the filling body–surrounding rock combination.The evaluated distances(ED)revealed a high sensitivity to the stability of the filling body–surrounding rock combination.The new method was then applied to calculate the time series of historically ED for 12 measuring points located at Longshou Mine.The moments of mutation in these time series were at least 3 months ahead of the roadway return dates.In the ED prediction experiments,the autoregressive integrated moving average model showed a higher prediction accuracy than the deep learning models(long short-term memory and Transformer).Furthermore,the root-mean-square error distribution of the prediction results peaked at 0.26,thus outperforming the no-prediction method in 70%of the cases.

Analysis of the Effectiveness of Modified Non- Traumatic Filling Technology in the Treatment of Pediatric Dental Caries

Objective:To analyze the effectiveness of modified non-traumatic filling technology in the treatment of pediatric dental caries.Methods:Ninety-seven children with dental caries who were treated in our hospital(Panyu Maternal and Child Care Service Center of Guangzhou)from January 2022 to December 2023 were selected and randomly divided into two groups,with 48 cases in the experimental group and 49 in the control group.The experimental group was treated with modified non-traumatic filling techniques,while the control group was treated with conventional filling techniques.Observation indicators such as the total effectiveness of the treatment,incidence of adverse events,treatment compliance,and pain scores were analyzed after the intervention.Result:After intervention,the total effectiveness of the treatment in the experimental group was higher than that in the control group(P<0.05).The incidence of adverse events in the experimental group was lower than that of the control group(P<0.05).The treatment compliance of patients in the experimental group was higher than that in the control group(P<0.05).The pain score of the experimental group was lower than that of the control group(P<0.05).Conclusion:The application of modified non-traumatic filling technology in the treatment of pediatric dental caries showed good therapeutic outcomes.After the intervention,the child’s symptoms were significantly alleviated,the incidence of adverse events such as filling material falling off was reduced,their compliance was improved,and the pain was relieved.This procedure is worth to be promoted for clinical application.

Tuning Active Metal Atomic Spacing by Filling of Light Atoms and Resulting Reversed Hydrogen Adsorption-Distance Relationship for Efficient Catalysis

Precisely tuning the spacing of the active centers on the atomic scale is of great significance to improve the catalytic activity and deepen the understanding of the catalytic mechanism,but still remains a challenge.Here,we develop a strategy to dilute catalytically active metal interatomic spacing(d_(M-M))with light atoms and discover the unusual adsorption patterns.For example,by elevating the content of boron as interstitial atoms,the atomic spacing of osmium(d_(Os-Os))gradually increases from 2.73 to 2.96?.More importantly,we find that,with the increase in dOs-Os,the hydrogen adsorption-distance relationship is reversed via downshifting d-band states,which breaks the traditional cognition,thereby optimizing the H adsorption and H_2O dissociation on the electrode surface during the catalytic process;this finally leads to a nearly linear increase in hydrogen evolution reaction activity.Namely,the maximum dOs-Os of 2.96?presents the optimal HER activity(8 mV@10 mA cm^(-2))in alkaline media as well as suppressed O adsorption and thus promoted stability.It is believed that this novel atomic-level distance modulation strategy of catalytic sites and the reversed hydrogen adsorption-distance relationship can shew new insights for optimal design of highly efficient catalysts.

Raw Gangue Filling Mining under Construction —A Case Study in China

In order to recover the strip pillar coal resources, reduce the amount of gangue mountain and realize remediation of the goaf environment in the old mining area, the raw gangue filling mining technology was proposed. According to the previous practical experience, the feasibility of the implementation of raw gangue filling mining technology in the coal-pressed area was analyzed. Through the filling gangue compaction test, the deformation under different loading stages was obtained. Further, a reasonable prediction of the deformation beyond the experimental limited loading load was made based on the experimental results. Through the deformation source analysis of the whole process of gangue filling, the key factors for controlling deformation before, during, and after filling were determined. Additionally, the proportion of deformation during different stages was quantified. Considering the protection of surface buildings, mining fullness of the working face and mining technology, the production parameters of 1209 and 1210 filling working faces were preliminarily determined. Through numerical simulation, the rationality of mining scheme was verified. Based on the practice of 1209 working face and the key factors to control the deformation of gangue filling, the mining system and process in 1210 working face were optimized. According to the measured surface rock movement, raw gangue filling mining technology can meet the requirements of surface building protection level. Especially, this paper provides a method to quantitatively calculate the equivalent mining height (EMH) of raw gangue filling and its mining deformation, which has reference significance for old mining areas.

FGW1, a protein containing DUF630 and DUF632 domains, regulates grain size and filling in Oryza sativa L.

Grain filling influences grain size and quality in cereal crops. The molecular mechanisms that regulate grain endosperm development remain elusive. In this study, we characterized a filling-defective and grain width mutant, fgw1, whose mutation increased rice seed width mainly via cell division and expansion in grains. Sucrose contents were higher but starch contents lower in the fgw1 mutant during the grainfilling stage, resulting in inferior endosperm of opaque, white appearance with loosely packed starch granules. Map-based cloning revealed that FGW1 encoded a protein containing DUF630/DUF632domains, localized in the plasma membrane with preferential expression in the panicle. RNA interference in FGW1 resulted in increased grain width and weight, whereas overexpression of FGW1 led to slightly narrower kernels and better grain filling. In a yeast two-hybrid assay, FGW1 interacted directly with the 14–3–3 protein GF14f, bimolecular fluorescence complementation verified that the site of interaction was the membrane, and the mutated FGW1 protein failed to interact with GF14f. The expression of GF14f was down-regulated in fgw1, and the activities of AGPase, StSase, and SuSase in the endosperm of fgw1increased similarly to those of a reported GF14f-RNAi. Transcriptome analysis indicated that FGW1 also regulates cellular processes and carbohydrate metabolism. Thus, FGW1 regulated grain formation via the GF14f pathway.

Effects of Heat Stress during Seed Filling Stage on Brassica napus Seed Oil Accumulation and Chlorophyll Fluorescence Characteristics

As global temperature rise,the threat of heat stress to rapeseed production is becoming more obvious.Exploring the response characteristics of two important biological pathways,oil accumulation and photosynthesis,to heat stress during B.napus seed filling is helpful in the genetic improvement of heat-tolerant rapeseed.The effects of heat stress on seed oil accumulation and chlorophyll fluorescence characteristics of 29 B.napus germplasms with different oil content and environmental sensitivity,including 6 rapeseed varieties which exhibited environmentsensitive/insensitive and with high,medium or low oil content,were tested by whole plant heat stress or the in vitro silique culture system.Both assay exhibited similar trend on oil content of the rapeseed germplasms.The heat effect on the chlorophyll fluorescence kinetic parameters F_(v)/F_(m),ETR and Y(Ⅱ)were also consistent.Heat stress significantly decreased oil content,although there was abundant genetic variation on heat tolerance among the genotypes.Correlation analysis showed that the decrease rate of F_(v)/F_(m) of silique heat-stressed B.napus developing seed was positive correlative to the decrease rate of mature seed oil content of the whole plant heat-stressed rapeseed(R=0.9214,P-value<0.01).Overall,the results indicated that heat stress inhibited oil accumulation and photosynthesis in B.napus developing seed.The decrease rate of chlorophyll fluorescence parameter F_(v)/F_(m) of heat-stressed developing seed could be used as the index of heat tolerant rapeseed identification.Further,two heat insensitive rapeseed varieties with high oil content were identified.

Effects of mechanical vibration on filling and solidification behavior, microstructure and performance of Al/Mg bimetal by lost foam compound casting

Al/Mg bimetal was prepared by lost foam solid-liquid compound casting,and the effects of mechanical vibration on the filling and solidification behavior,microstructure and performance of the bimetal were investigated.Results show that the mechanical vibration has a remarkable influence on the filling and solidification processes.It is found that after mechanical vibration,the filling rate increases and the filling rate at different times is more uniform than that without vibration.In addition,the mechanical vibration also increases the wettability between liquid AZ91D and A356 inlays.The mechanical vibration reduces the horizontal and vertical temperature gradient of the casting and makes the temperature distribution of the whole casting more uniform.Compared to the Al/Mg bimetal without vibration,the shear strength is improved by 39.76%after the mechanical vibration is applied,due to the decrease of the inclusions and Al_(12)Mg_(17) dendrites,and the refinement and uniform distribution of the Mg_(2)Si particles in the interface of the Al/Mg bimetal.

Study of the spatial growth of stimulated Brillouin scattering in a gas-filled hohlraum via detecting the driven ion acoustic wave

In an experiment performed on the Shenguang-III prototype laser facility, collective Thomson scattering (TS) is used to study the spatialgrowth of stimulated Brillouin scattering (SBS) in a gas-filled hohlraum by detecting the SBS-driven ion acoustic wave. High-quality timeresolved SBS and TS spectra are obtained simultaneously in the experiment, and these are analyzed by a steady-state code based on theray-tracing model. The analysis indicates that ion–ion collisions may play an important role in suppressing SBS growth in the Au plasma;as aresult, the SBS excited in the filled gas region is dominant. In the early phase of the laser pulse, SBS originates primarily from the high-densityplasma at the edges of the interaction beam channel, which is piled up by the heating of the interaction beam. Throughout the duration of thelaser pulse, the presence of the TS probe beam might mitigate SBS by perturbing the density distribution around the region overlapping withthe interaction beam.

Fulfilling Meetings

The annual Two Sessions highlight high-quality development The 14th National People’s Congress (NPC),China’s national legislature, concluded its first session on the morning of 13 March in Beijing,marking the completion of the annual sessions of the NPC and the National Committee of the Chinese People’s Political Consultative Conference (CPPCC), the top political advisory body,known collectively as Two Sessions.

一种基于红外成像障碍物检测的改进Flood Filling算法

在对图像特征进行有效分割的基础上,提出了一种基于红外成像障碍物检测的改进Flood Filling算法,并首次将该算法应用到障碍物检测领域中。通过对模拟以及真实红外图像中目标的快速成功提取,不仅验证了该方法的有效性,同时实验结果也表明了其较之原始算法对时效性的提高。

Effects of Lodging at Different Filling Stages on Rice Yield and Grain Quality

The effects of lodging of rice plants from 20 d after full heading to maturity on yield and grain quality were investigated with a hybrid rice combination Liangyoupeijiu and a japonica rice cultivar CY-6. The results showed that, except for brown rice rate, almost all parameters for yield and grain quality including ratio of grain length to grain width, gelatinization temperature and gel consistency, were significantly influenced by lodging and thus deteriorated. Regression analysis suggested that, lodging one day earlier at the grain-filling stage could cause 2.66% to 2.71% of yield loss, 1.8 to 2.6 percentage points decrease of seed-setting rate, 0.26 to 0.32 g reduction of lO00-grain weight, 0.097 to 0. 155 percentage point decline of milled rice rate, as well as 0.13 to 0.27 percentage point increase of chalky grain rate, and 0.021 to 0.024 percentage point rise of protein content, and subsequently lower the eating quality.

HYDRODYNAMIC SIMULATION TO MOLD FILLING UNDER COUNTER GRAVITY

In situ observations of the flow morphology during mold filling under counter gravity are conducted on a perspex water model by means of flow visualization, high speed photography and pattern processing. The experimental results indicate that influences of the dynamic factors on flow morphology can be expressed quantitatively with the parameterφ(k). The flow field takes on different morphology with change in values of φ(k). For thick and thin walled castings, the main dynamic factors influencing flow morphology are gravity and surface tension respectively. Under general circumstances, F_r and W_e should be equal in their values to guarantee the similarity between the prototype and the model in simulating mold filling under counter gravity by experiment.

Changes in Activities of the Key Enzymes Related to Starch Synthesis in Rice Grains During Grain Filling and Their Relationships with the Filling Rate and Cooking Quality

With 10 rice cultivars (lines) as materials, the changes in activities of adenosine diphosphoglucose pyrophosphorylase(ADPGPase), starch synthase (SSase) and starch branching enzyme (Q-enzyme) in the grains during grain filling, and theirrelationships with the filling rate, gel consistency (GC), alkali spreading value (ASV) and amylose content (AC) werestudied. The results showed that changes in activities of ADPGPase, SSase and Q-enzyme exhibited a single peak duringgrain filling, and the time of the activity peaks for the former two enzymes was earlier than that of the maximum grain-fillingrate (Tmax), and the time reaching the peak for Q-enzyme was synchronous with Tmax. The activities at early grain fillingstage, and the mean and maximum activities of each enzyme during grain filling period were positively and significantly orvery significantly correlated with the mean and maximum grain filling rate and starch content (mg grain-1) in the grains.Activities of ADPGPase at all grain filling stages and those of Q-enzyme at the early and mid filling stages were notsignificantly correlated the cooking quality (GC, ASV and AC). SSase activities at the early filling stage were significantlyand negatively correlated with GC and ASV, and positively correlated with AC. Activities of SSase at mid and late grainfilling stages and Q-enzyme at the late filling stage were significantly and positively correlated with GC and ASV, andnegatively correlated with AC. Spraying zeatin or abscisic acid at early grain filling stage could obviously regulate theactivities of ADPGPase, SSase and Q-enzyme in the grains.

Combined effect of shading time and nitrogen level on grain filling and grain quality in japonica super rice

There is limited information about the combined effect of shading time and nitrogen （N） on grain filling and quality of rice. Therefore, two japonica super rice cultivars, Nanjing 44 and Ningjing 3, were used to study the effect of shading time and N level on the characteristics of rice panicle and grain filling as well as the corresponding yield and quality. At a low N level （150 kg N ha^-1, 150N）, grain yield decreased （by 21.07-26.07%） under the treatment of 20 days of shading before heading （BH） compared with the no shading （NS） treatment. These decreases occurred because of shortened panicle length, decreased number of primary and secondary branches, as well as the grain number and weight per panicle. At 150N, in the treatment of 20 days of shading after heading （AH）, grain yield also decreased （by 9.46-10.60%） due to the lower grain weight per panicle. The interaction of shading and N level had a significant effect on the number of primary and secondary branches. A high level of N （300 kg N ha^-1, 300N） could offset the negative effect of shading on the number of secondary branches and grain weight per panicle, and consequently increased the grain yield in both shading treatments. In superior grains, compared with 150N NS, the time to reach 99% of the grain weight （T99） was shortened by 1.6 to 1.7 days, and the grain weight was decreased by 4.18-5.91% in 150N BH. In 150N AH, the grain weight was 13.39-13.92% lower than that in 150N NS due to the slow mean and the maximum grain-filling rate （GRmean and GRmax）. In inferior grains, grain weight and GRmean had a tendency of 150N NS〉150N BH〉150N AH. Under shaded conditions, 300N decreased the grain weight due to lower GReen both in superior and inferior grains. Compared with 150N NS, the milling and appearance qualities as well as eating and cooking quality were all decreased in 150N BH and 150N AH. Shading with the high level of 300N improved the milling quality and decreased the number of chalky rice kernels, but the eating and cooking quality was reduced with increased chalky area and overall chalkiness. Therefore, in the case of short term shading, appropriate N fertilizer could be used to improve the yield and milling quality of rice, but limited application of N fertilizer is recommended to achieve good eating and cooking quality of rice.

Mapping QTL for Heat-Tolerance at Grain Filling Stage in Rice

A mapping population of 98 lines (backcross inbred lines, BILs) derived from a backcross of Nipponbare/Kasalath// Nipponbare was planted at two experimental sites, Nanjing and Nanchang, and treated with high and optimal temperature during grain filling, respectively. The grain weight heat susceptibility index [GWHSI= (grain weight at optimum temperature-grain weight at high temperature) / grain weight at optimum temperature × 100] was employed to evaluate the tolerance of rice to heat stress. A genetic linkage map with 245 RFLP markers and a mixed linear-model approach was used to detect quantitative trait loci (QTLs) and their main effects, epistatic interactions and QTL× environment interactions (Q×E). The threshold of LOD score=2.0 was used to detect the significance of association between marker and trait. A total of 3 QTLs controlling heat tolerance during grain filling were detected, on chromosomes 1, 4 and 7, with LOD scores of 8.16, 11.08 and 12.86, respectively, and they explained the phenotypic variance of 8.94, 17.25 and 13.50 %, correspondingly. The QTL located in the C1100-R1783 region of chromosome 4 showed no QTL× environment interaction and epistatic effect, suggesting that it could be stably expressed in different environments and genetic backgrounds, and thus it would be valuable in rice breeding for heat tolerance improvement. This QTL allele, derived from Kasalath reduced 3.31% of the grain weight loss under heat stress. One located between R1613-C970 on chromosome 1 and the other between C1226-R1440 on chromosome 7, with additive effect 2.38 and 2.92%, respectively. The tolerance alleles of both these QTLs were derived from Nipponbare. Both of these QTLs had significant QTL× environment interactions, and the latter was involved in epistatic interaction also. Eight pairs of epistatic effect QTLs were detected, one pair each on chromosomes 1,2,3, 5, 7, 8, 10 and 12. The results could be useful for elucidating the genetic mechanism of heat-tolerance and the development of new rice varieties with heat tolerance during grain filling phase.

Changes in Enzyme Activities Involved in Starch Synthesis and Hormone Concentrations in Superior and Inferior Spikelets and Their Association with Grain Filling of Super Rice

The changes in activities of key enzymes involved in sucrose-to-starch conversion and concentrations of hormones in superior and inferior spikelets of super rice were investigated and their association with grain filling was analyzed.Four super rice cultivars,Liangyoupeijiu,IIyou 084,Huaidao 9 and Wujing 15,and two high-yielding and elite check cultivars,Shanyou 63 and Yangfujing 8,were used.The activities of sucrose synthase （SuSase）,adenosine diphosphoglucose pyrophosphorylase （AGPase）,starch synthase （StSase） and starch branching enzyme （SBE）,and the concentrations of zeatin ＋ zeatin riboside （Z ＋ ZR）,indole-3-acetic acid （IAA） and abscisic acid （ABA） in superior and inferior spikelets were determined during the grain filling period and their relationships with grain filling rate were analyzed.Maximum grain filling rate,the time reaching the maximum grain-filling rate,mean grain filling rate and brown rice weight for superior spikelets showed a slight difference between the super and check rice cultivars,but were significantly lower in the super rice than in the check rice for inferior spikelets.Changes of enzyme activities and hormone concentrations in grains exhibited single peak curves during the grain filling period.The peak values and the mean activities of SuSase,AGPase,StSase and SBE were lower in inferior spikelets than in superior ones,as well as the peak values and the mean concentrations of Z ＋ ZR and IAA.However,the peak value and the mean concentration of ABA were significantly higher in inferior spikelets than in superior ones and greater in the super rice than in the check rice.The grain filling rate was positively and significantly correlated with the activities of SuSase,AGPase and StSase and the concentrations of Z ＋ ZR and IAA.The results suggested that the low activities of SuSase,AGPase and StSase and the low concentrations of Z ＋ ZR and IAA might be important physiological reasons for the slow grain filling rate and light grain weight of inferior spikelets in super rice.

Oil filling history of the Bashituo Oilfield in the Markit Slope,SW Tarim Basin,China

The Markit Slope is an important area for the petroleum exploration in the Tarim Basin. Elucidation of the oil filling history of discovered oilfields has great significance for recognizing the accumulation processes of the whole region. Using molecular geochemistry, fluid inclusion techniques and basin modeling, we studied the oil filling process of the Bashituo Oilfield that is located in the west of the Markit Slope. The molecular migration indexes, such as the methyldibenzothiophene ratio （4-/1-MDBT）, trimethylnaphthalene ratio （TMNr） and pyrrolic nitrogen compounds content, decrease from west to east, indicating that the charging direction and migration pathways are from west to east. Lithological analysis and homogenization temperatures of saline fluid inclusions accompanied with oil fluid inclusions suggest that two charging periods occurred in the Devonian oil reservoir. Combining the burial history and heating history of well BT4, Basinmod 1D software modeling shows the two oil filling periods are from 290 Ma to 285 Ma and from l0 Ma to 4 Ma, respectively, and later oil filling dominates. This study may be helpful to understand the accumulation process and provide useful references for oil and gas exploration in the Markit Slope.

The causes and impacts for heat stress in spring maize during grain filling in the North China Plain--A review

High-temperature stress （HTS） at the grain-filling stage in spring maize （Zea mays L.） is the main obstacle to increasing productivity in the North China Plain （NCP）. To solve this problem, the physiological mechanisms of HTS, and its causes and impacts, must be understood. The HTS threshold of the duration and rate in grain filling, photosynthetic characteristics （e.g., the thermal stability of thylakoid membrane, chlorophyll and electron transfer, photosynthetic carbon assimilation）, water status （e.g., leaf water potential, turgor and leaf relative water content） and signal transduction in maize are reviewed. The HTS threshold for spring maize is highly desirable to be appraised to prevent damages by unfavorable temperatures during grain filling in this region. HTS has negative impacts on maize photosynthesis by damaging the stability of the thylakoid membrane structure and degrading chlorophyll, which reduces light energy absorption, transfer and photosynthetic carbon assimilation. In addition, photosynthesis can be deleteriously affected due to inhibited root growth under HTS in which plants decrease their water-absorbing capacity, leaf water potential, turgor, leaf relative water content, and stomatal conductance. Inhibited photosynthesis decrease the supply of photosynthates to the grain, leading to falling of kernel weight and even grain yield. However, maize does not respond passively to HTS. The plant transduces the abscisic acid （ABA） signal to express heat shock proteins （HSPs）, which are molecular chaperones that participate in protein refolding and degradation caused by HTS. HSPs stabilize target protein configurations and indirectly improve thylakoid membrane structure stability, light energy absorption and passing, electron transport, and fixed carbon assimilation, leading to improved photosynthesis. ABA also induces stomatal closure to maintain a good water status for photosynthesis. Based on understanding of such mechanisms, strategies for alleviating HTS at the grain-filling stage in spring maize are summarized. Eight strategies have the potential to improve the ability of spring maize to avoid or tolerate HTS in this study, e.g., adjusting sowing date to avoid HTS, breeding heat-tolerance varieties, and tillage methods, optimizing irrigation, heat acclimation, regulating chemicals, nutritional management, and planting geometric design to tolerate HTS. Based on the single technology breakthrough, a com- prehensive integrated technical system is needed to improve heat tolerance and increase the spring maize yield in the NCP.

Top-grain filling characteristics at an early stage of maize(Zea mays L.) with different nitrogen use efficiencies

Maize genotypes vary significantly in their nitrogen use efficiencies（NUEs）.Better understanding of early grain filling characteristics of maize is important,especially for maize with different NUEs.The objectives of this research were（i）to investigate the difference in apical kernel development of maize with different NUEs,（ii）to determine the reaction of apical kernel development to N application levels,and（iii）to evaluate the relationship between apical kernel development and grain yield（GY）for different genotypes of maize.Three maize hybrid varieties with different NUEs were cultivated in a field with different levels of N fertilizer arranged during two growing seasons.Kernel fresh weight（KFW）,volume（KV）and dry weight（KDW）of apical kernel were evaluated at an early grain filling stage.Ear characteristics,GY and its components were determined at maturity stage.Apical kernel of the high N and high efficiency（HN-HE）type（under low N,the yield is lower,and under higher N,the yield is higher）developed better under high N（N210 and N240,pure N of 210 and 240 kg ha^–1）than at low N（N120 and N140,pure N of 120 and 140 kg ha^–1）.The low N and high efficiency（LN-HE）type（under low N,the yield is higher,while under higher N,the yield is not significantly higher）developed better under low N than at high N.The double high efficiency（D-HE）type（for both low and high N,the yield is higher）performed well under both high and low N.Apical kernel reacted differently to the N supply.Apical kernel developed well at an early grain filling stage and resulted in a higher kernel number（KN）,kernel weight（KW）and GY with better ear characteristics at maturity.