甲基磺酸乙酯(EMS)对谷子种子及幼苗活力的影响

为了探明甲基磺酸乙酯(EMS)诱变嫩选18种子构建突变体库的最适条件,加快品种选育进程,本研究对嫩选18种子进行了3种处理时间、3种EMS处理浓度的化学诱导,并对M1种子发芽及幼苗生长的诱变效应进行研究。结果表明:与对照相比,EMS处理在浓度0.4%下浸种6 h对嫩选18的发芽率及幼苗生长影响差异不显著,随着EMS浸种浓度、时间增加,种子萌发及幼苗生长逐渐受到抑制,在1.2%浓度下浸种14 h对种子萌发及幼苗生长抑制作用最强,极大降低了嫩选18的发芽势、发芽率、成苗率,并且导致幼苗生长缓慢。以存活率达到50%为标准,通过回归方程计算出在6 h、10 h、14 h浸种时间下,EMS浓度的半致死剂量分别为0.99%、0.72%、0.38%,可作为嫩选18 EMS诱变建立突变体库的适合条件。

不同EMS处理时间对大豆诱变后代主要品质含量变化影响分析

为探究不同EMS处理时间对大豆诱变后代主要品质含量变化的影响,文章利用0.5%EMS溶液处理大豆高蛋白品系公交1057-1,分别浸泡4、7和10 h(清水冲洗处理为对照),对播种后获得的连续4代诱变后代主要品质含量变化进行分析。结果表明,与对照相较,经EMS处理后的植株成活率随处理时间延长而降低。其中,经EMS-4处理后的植株成活率最高,为43.5%;经EMS-10处理后的植株成活率最低,仅为16.0%。不同EMS处理时间对大豆诱变后代的蛋白质含量影响显著,对脂肪含量影响不明显。其中经EMS-4处理的诱变后代蛋白质含量高于其他3组处理;经EMS-4处理后的M2代蛋白质含量发生显著分离,并出现超亲个体,脂肪含量变化不显著。

达乌里胡枝子愈伤组织及种子EMS诱变研究

为优化达乌里胡枝子愈伤诱导培养基的激素含量及比例,明确甲基磺酸乙酯(EMS)诱变愈伤组织及种子的最佳条件,本研究以达乌里胡枝子种子为外植体,探究了不同激素配比对愈伤诱导的影响,并针对愈伤组织和种子处理分别设置了两时间两浓度(2 h和6 h,0.3%和0.9%)及三时间两浓度(6 h、8 h、10 h,0.4%、0.8%)的EMS处理时间和浓度的组合,研究各处理对愈伤分化系数和后期植株成活率以及种子发芽率、发芽势和幼苗表型变异的影响。结果表明,达乌里胡枝子种子愈伤的最佳激素配比为0.25 mg/L NAA+0.5 mg/L 6-BA+0.5 mg/L 2,4-D,此时达乌里胡枝子愈伤诱导率为94.9%。EMS诱变达乌里胡枝子愈伤组织的适宜浓度为0.3%,处理时间为6 h,分化系数和植株相对成活率分别为46.31%和47.78%,接近半致死范围,且生根数、根长和平均株高等指标与高浓度EMS处理相比受到的负面影响较小。EMS诱变达乌里胡枝子种子的适宜浓度为0.8%,处理时间10 h,发芽率、出苗率、成苗率分别为53.61%、51.06%和53.28%,均接近半致死量,同时发现多株幼苗叶片出现了明显的形态变异。本试验在达乌里胡枝子原有种质资源基础上,丰富了达乌里胡枝子突变体库,也为后续开展达乌里胡枝子诱变育种研究提供理论依据。

EMS诱变对鹰嘴紫云英种子萌发及幼苗表型特征的影响

【目的】筛选适宜鹰嘴紫云英的EMS诱变条件。【方法】以鹰嘴紫云英品种甘绿2号种子为试验材料,采用不同浓度(0、0.2%、0.4%、0.6%、0.8%)的甲基磺酸乙酯(EMS)进行不同时间(2、4、6、8 h)的诱变处理,探究EMS对鹰嘴紫云英种子萌发特征及表型变化的影响。【结果】低浓度和短时间EMS处理促进鹰嘴紫云英种子的萌发,随EMS浓度升高和诱变时间的增加,对鹰嘴紫云英种子萌发产生抑制作用。种子浸出液电导率随诱变条件的加深呈上升趋势,在2~6 h时,萌发期发芽率、发芽势、幼苗苗长和根长均随处理时间和诱变浓度的增加呈先升高后降低的趋势,在8 h处理下,随EMS浓度的增加呈逐渐降低趋势,EMS浓度在0.8%时,种子发芽率和发芽势均达到最低,较对照分别降低了54.45%和56.67%;经形态学筛选,发现有鹰嘴紫云英幼苗表现出幼苗矮小、停滞生长、叶片黄化、宽叶、窄叶、叶片发紫、诸多病斑等特殊变异性状。【结论】0.8%EMS处理6 h可作为最佳诱变组合;幼苗的生长随诱变时间和浓度增加而明显受到抑制,且表型变异类型也逐步增多。

基于EMS管理模式的延续性护理在学龄前喘息性疾病儿童中的应用观察

目的·探讨基于EMS[环境管理(environment management,E)、用药指导(medicine direction,M)与自我监测(self monitoring,S)]管理模式的延续性护理在学龄前喘息性疾病儿童中的应用效果。方法·选取2019年12月至2020年11月,在上海交通大学医学院附属儿童医院呼吸科收治的67例0~6岁喘息性疾病患儿,按照随机数字表分为观察组33例和对照组34例,其中失访3例,最终每组32例。观察组采用基于EMS管理模式的延续性护理,对照组给予常规护理和出院电话随访。2组患儿出院后1、3、6个月随访评估儿童呼吸和哮喘测试(Test for Respiratory and Asthma Control in Kids,TRACK)结果、喘息复发情况;出院后6个月随访采用支气管哮喘用药依从性评分表(Medication Adherence Report Scale for Asthma,MARS-A)和护理工作满意度调查表评估用药依从性及护理工作满意度。结果·2组患儿人口学特征及临床基线特征差异无统计学意义。重复测量方差分析结果显示,时间、组别、组别×时间的交互作用对TRACK总分的影响均有统计学意义;出院后1、3、6个月,观察组TRACK总分均显著高于对照组(均P=0.000);2组患儿TRACK总分均随时间推移逐渐上升(P=0.000)。观察组1、3、6个月随访发现喘息复发率分别为25.0%、18.7%、9.4%,均显著低于对照组(分别为50.0%、43.7%、31.3%,均P<0.05);广义估计方程分析显示组间比较差异有统计学意义(P=0.013),观察组干预效果优于对照组(OR=0.292)。出院后6个月观察组MARS-A得分为(4.519±0.395)分,显著高于对照组[(3.994±0.739)分,P=0.001]。护理工作满意度调查结果显示,观察组显著高于对照组(P=0.000)。患儿MARS-A得分与护理工作满意度呈中度正相关(r=0.389,P=0.001)。结论·基于EMS管理模式的延续性护理可显著提高学龄前喘息性疾病儿童的用药依从性和喘息控制水平,明显降低喘息复发率,以及提高护理工作满意度。

籽用美洲南瓜EMS诱变突变体库的构建及表型分析

【目的】构建籽用美洲南瓜突变体库,加快籽用美洲南瓜种质资源创新进程,对南瓜品种选育、品种改良以及遗传基础的拓宽具有重要的意义。【方法】利用1.8%诱变剂甲基磺酸乙酯(EMS)处理籽用美洲南瓜ZHL4种子15 h,然后对M_(1)和M_(2)代群体单株进行表型变异观察,同时对M_(2)群体变异株系ZHL4-33进行显微组织结构观察。【结果】(1)M_(2)群体中共筛选到242个突变植株,45种表型变异,变异类型涵盖了突变株的各个生长时期以及各植物器官,总的突变频率达到25.17%。(2)突变体叶片栅栏组织厚度显著高于野生型,排列紧凑,维管形成层痕迹明显;突变体茎维管束多而密集,导管直径小于野生型,髓部发达,细胞间隙较小,细胞数目有所增加。【结论】初步构建了由425个M_(2)家系所组成的籽用美洲南瓜突变体库,为籽用美洲南瓜功能基因组研究和新品种选育奠定了材料基础。

EMS诱变对大麦种子萌发及M_(1)代植株成熟期主要性状的影响

为探究甲基磺酸乙酯(EMS)对大麦种子萌发及M_(1)代植株成熟期主要表型性状突变的影响,以啤酒大麦品种新啤6号为材料,分别用0.00%、0.05%、0.10%、0.15%和0.20%的EMS浸种10 h,分析各浓度EMS处理对种子发芽势、发芽率、致死率、畸变率、幼苗叶绿素含量、根系活力和形态指标的影响,记录0.10%EMS诱变后M_(1)代成熟期植株主要性状的突变类型和突变频率。结果表明,EMS明显抑制种子萌发和幼苗生长,并产生了大量的性状突变。与对照相比,0.10%EMS浸种显著降低了种子发芽势、发芽率、幼苗叶绿素含量和根系活力,致死率和畸变率显著提高;0.15%和0.20%EMS浸种显著降低了幼苗根和芽的长度、鲜重和干重,胚芽鞘干重显著提高。田间统计发现,0.10%EMS处理的M_(1)代植株主要突变性状集中在茎秆、叶片、穗形和育性等方面,产生了红秆、矮秆、红叶、芒卷、穗畸形、结实率低和分蘖少等性状,突变频率分别20.17%、4.87%、1.08%、16.67%、0.94%、14.00%和6.02%。因此,通过EMS诱变构建大麦突变体库和创制种质资源。

不同浓度EMS诱变不结球白菜的效果分析

为创制不结球白菜新种质,发掘新基因,探索不同浓度甲基磺酸乙酯(ethyl methane sulfonate,EMS)对不结球白菜的诱变效应。采用浓度为0.4%、0.6%和0.8%的EMS溶液对4个不结球白菜品种[黑塌菜(HTC)、香青菜(XQC)、JP241、XWZ]进行种子诱变处理,调查种子发芽情况与田间植株农艺性状表现。结果表明:4个不结球白菜品种的种子发芽势、发芽率和相对成苗率均随着EMS浓度的升高而逐渐降低,且处理间差异显著。EMS诱变可以引起不结球白菜叶色、叶形、株型、花器官等性状发生变异。不同品种不结球白菜的EMS诱变半致死剂量有所不同,产生的变异种类和变异频率也有所不同,HTC的半致死剂量为0.8%,相对变异频率为23.83%;XQC的半致死剂量为0.8%,相对变异频率为17.61%;JP241的半致死剂量为0.6%,相对变异频率为38.45%;XWZ的半致死剂量为0.6%,相对变异频率16.69%。EMS的浓度越高,诱变的不结球白菜始花开放时间越晚,莲座叶叶片数越少,雄性不育率越高。

EMS诱变的水稻不同位点突变体对ALS抑制剂类除草剂抗性差异

稻田杂草严重威胁水稻生长,培育抗除草剂水稻新品种,是高效解决稻田杂草危害的重要途径之一。本研究利用甲基磺酸乙酯(EMS)对华占水稻进行化学诱变,创建突变体,利用乙酰乳酸合成酶(ALS)抑制剂类除草剂甲咪唑烟酸(20 g/hm 2,有效成分)对突变体进行筛选,获得抗甲咪唑烟酸突变体材料,并对上述突变体的OsALS基因序列进行分析,明确其突变类型。最后对不同突变类型对甲氧咪草烟和甲基二磺隆的交互抗性进行分析。结果表明,华占水稻经EMS诱变和甲咪唑烟酸筛选后共获得11株抗甲咪唑烟酸突变体材料,其突变类型为Pro171Leu、Ser627Cys、Ser627Asn和Gly628Glu 4种。其中,Ser627Cys为首次发现的突变类型。4种突变类型对甲咪唑烟酸的抗性水平存在一定的差异,Ser627Asn、Ser627Cys、Pro171Leu、Gly628Glu突变类型的抗性指数分别为8.71、5.16、3.28和3.69。4种突变类型对甲氧咪草烟和甲基二磺隆的抗性亦存在显著差异。其中,Ser627Asn突变类型对甲氧咪草烟的抗性最高,抗性指数为20.57,Gly628Glu对甲基二磺隆抗性最高,抗性指数为5.11。综上,本研究通过EMS诱变获得了4种抗ALS抑制剂类除草剂的华占水稻突变类型,并鉴定了其对甲咪唑烟酸的抗性差异及对甲氧咪草烟和甲基二磺隆的交互抗性,为进一步的抗除草剂水稻品种培育和除草剂轮换使用提供依据。

EMS诱变菜豆子叶节定向筛选耐羟脯氨酸(HYP)突变体

以双丰一号菜豆子叶节为外植体,利用化学诱变剂EMS处理引发基因突变,进行突变体定向筛选抗逆突变细胞系。以0.17%EMS诱变处理2 h,子叶节的不再生率接近50%;以羟脯氨酸最大致死量3.5 mmol/L为筛选压力,定向筛选抗逆突变体。结果显示,在羟脯氨酸筛选培养基上,经EMS诱变的子叶节存活31个,突变率为8.61%,存活的子叶节再生率为74.19%,成功获得耐羟脯氨酸的突变株系。

上海某院EMS转运急性缺血性脑卒中患者院前延误的回顾性研究

目的 探究启动EMS(emergency medical service,紧急医疗服务)转运的急性缺血性脑卒中患者院前延误的影响因素,为急性缺血性脑卒中患者减少延误提高策略。方法 对132例启动EMS的急性缺血性脑卒中患者进行相关影响因素分析,包括年龄、性别、呼救时天气情况、脑卒中知识认知度,首发症状等,分为延误组(n=29)和及时组(n=103),通过多因素Logistics回归分析确定造成院前延误的影响因素。结果 两组患者在不同天气情况、卒中知识认知度、首发症状上存在差异(P<0.05)。多因素Logistics回归分析显示天气情况(OR=0.581,95%CI:0.358~0.943),卒中知识认知度(OR=0.238,95%CI:0.098~0.578)及首发症状为意识障碍(OR=0.076,95%CI:0.008~0.717)是减少院前延误的独立影响因素(P<0.05)。结论 较高卒中知识认知度、首发症状有意识障碍、天气情况良好有利于减少启动EMS转运的急性缺血性脑卒中患者的院前延误。因此,加强公众卒中知识普及培训,提高公众卒中意识,尽快启动EMS系统,可减少院前延误,改善患者预后。

保护装置交流回路EMS测试对源影响的研究

在继电保护电磁兼容标准中,对于保护装置交流回路端口有严格的电磁兼容抗扰度试验要求。作为一种辅助设备或回路——给保护装置交流采样回路加激励量的“源”,必须保持“干净”,这是抗干扰性能测试的重要影响因素。“源”干净与否,会对测试结果本身产生重要影响。本文旨在分析这些影响原因,并对如何消除影响提出了一些建议。

Effect of Butternut Squash (Cucurbita moschata) Seed Powder on the Chemical and Rheological Properties of Stirred Cultured Camel Milk and Yoghurt

Research shows that producing fermented camel milk is hard because of the milk’s inability to form a firm coagulum, attributed to low levels of κ-casein and ꞵ-lactoglobulin and the large casein micelle size, leading to a weak network of casein formation. In an effort to address this issue, researchers turned to corn starch as a thickening agent, discovering that a concentration of 2.0% effectively improved the viscosity and significantly reduced syneresis in stirred camel milk yoghurt and cultured camel milk. This study explores alternatives to corn starch, focusing on butternut squash seeds as a promising substitute due to their hydrocolloid composition. By incorporating butternut squash (Cucurbita moschata) seed powder (BSSP) as a thickening agent, this study aimed at enhancing the chemical and rheological properties of stirred camel milk yoghurt and cultured camel milk. Fermented camel milk was prepared using 4 litres of camel milk, 2% starter cultures (thermophilic culture for yoghurt and mesophilic aromatic culture for stirred cultured camel milk) and BSSP 0.0% (negative control), 0.4%, 0.8%, 1.2%, 1.6%, 2.0% mixed with 0.4% gelatin. 2.0% corn starch mixed with 0.4% gelatin was used as a standard for comparison. Results showed that increasing the BSSP level significantly (p < 0.05) decreased the moisture content while increasing the total solid content of stirred fermented camel milk products. There was an increase in ash content with an increase in BSSP levels. There was a significant (p < 0.05) reduction in the pH, with an increase in BSSP levels in stirred fermented camel milk samples. Increasing the concentration of BSSP from 0.4% to 2.0% resulted in a significant (p < 0.05) increase in viscosity and a reduction in syneresis of stirred camel milk yoghurt and stirred cultured camel milk samples. This study demonstrated that BSSP effectively enhances the viscosity, reduces syneresis and increases acidity in stirred fermented camel milk products during storage.

Improvement of Microstructure and Mechanical Properties of Rapid Cooling Friction Stir-welded A1050 Pure Aluminum

Two-mm thick A1050 pure aluminum plates were successfully joined by conventional and rapid cooling friction stir welding(FSW), respectively. The microstructure and mechanical properties of the welded joints were investigated by electron backscatter diffraction characterization, Vickers hardness measurements, and tensile testing. The results showed that liquid CO_(2) coolant significantly reduced the peak temperature and increased the cooling rate, so the rapidly cooled FSW joint exhibited fine grains with a large number of dislocations. The grain refinement mechanism of the FSW A1050 pure aluminum joint was primarily attributed to the combined effects of continuous dynamic recrystallization, grain subdivision, and geometric dynamic recrystallization. Compared with conventional FSW, the yield strength, ultimate tensile strength, and fracture elongation of rapidly cooled FSW joint were significantly enhanced, and the welding efficiency was increased from 80% to 93%. The enhanced mechanical properties and improved synergy of strength and ductility were obtained due to the increased dislocation density and remarkable grain refinement. The wear of the tool can produce several WC particles retained in the joint, and the contribution of second phase strengthening to the enhanced strength should not be ignored.

Multi-physical fields distribution in billet during helical electromagnetic stirring:A numerical simulation research

Electromagnetic stirring is one of the widely applied techniques to modify the quality of casting billets.Different from conventional rotate stirring,the helical stirring is more professional in assisting multi-dimensional flow of molten metal and eliminating solidification defects.In this study,the single-winding helical stirring(SWHS)was introduced,offering advantages such as smaller volume and lower electromagnetic shielding compared to traditional helical stirring methods.Following a comprehensive numerical simulation,the stirring parameters of SWHS were adjusted to yoke inclination angle of 43°and frequency of 12 Hz.The higher electromagnetic force and flow velocity in drawing direction,as well as the lower temperature gradient induced by the SWHS,are positive factors for homogeneous solidification of billet.The experimental results on Al-8%Si alloy and 0.4%C-1.1%Mn steel demonstrate that compared to rotate stirring,the SWHS process can induce better billet quality and is more effective in accelerating the equiaxed expansion and reducing element segregation.The SWHS process can enhance the equiaxed ratio of the billet by 58.3%and reduce segregation degree of carbon element by 10.97%.Consequently,SWHS holds great promise as a potential approach for improving the quality of continuous casting billets.

Tailoring the microstructure of Mg-Al-Sn-RE alloy via friction stir processing and the impact on its electrochemical discharge behaviour as the anode for Mg-air battery

Constructing the magnesium alloy with fine grains,low density of dislocations,and weak crystal orientation is of crucial importance to enhance its comprehensive performance as the anode for Mg-air battery.However,this unique microstructure can hardly be achieved with conventional plastic deformation such as rolling or extrusion.Herein,we tailor the microstructure of Mg-Al-Sn-RE alloy by using the friction stir processing,which obviously refines the grains without increasing dislocation density or strengthening crystal orientation.The Mg-air battery with the processed Mg-Al-Sn-RE alloy as the anode exhibits higher discharge voltages and capacities than that employing the untreated anode.Furthermore,the impact of friction stir processing on the electrochemical discharge behaviour of Mg-Al-Sn-RE anode and the corresponding mechanism are also analysed according to microstructure characterization and electrochemical response.

Modeling the Physical Parameters of Solenoids for MEMS Applications

The paper is devoted to study of the electrical parameters of the motion parts of the MEMS such as solenoids. The analytical background is given in order to describe the influence of the electrical field components on the forces, which are result of interaction of the electromagnetic (EM) field components with the parts of motion devices of MEMS. The given analytical formulas open the ability to calculate the self-inductance of the microsolenoids of the different kind, as well as the stored energy of such motion devices, that could be used for the modeling and optimization of parameters of running devices of MEMS such as actuators, sensors etc.

Mechanical properties and microstructural evolution of rheocast A356 semi-solid slurry prepared by annular electromagnetic stirring

Nowadays,having an effective technique in preparing semi-solid slurries for rheocasting process seems to be an essential requirement.In this study,semi-solid slurry of A356 aluminum alloy was prepared by three-phase annular electromagnetic stirring(A-EMS)technique under different conditions.The effects of stirring current,pouring temperature and stirring time on microstructural evolution,mean particle size,shape factor and solid fraction were investigated.The rheocasting process was carried out by using a drop weight setup and to inject the prepared semi-solid slurry in optimal conditions into the step-die cavity.The filling behavior and mechanical properties of parts were studied.Microstructural evolution showed that the best semi-solid slurry which had fine spherical particles with the average size of~27μm and a shape factor of~0.8 was achieved at the stirring current of 70 A,melt pouring temperature of 670℃,and stirring time of 30 s.Under these conditions,the step-die cavity was completely filled at die preheating temperature of 470℃.The hardness increases by decreasing step thickness as well as die preheating temperature.Moreover,the tensile properties are improved at lower die preheating temperatures.The fracture surface,which consists of a complex topography,indicates a typical ductile fracture.

监控画面信号自动巡视技术在电化学储能EMS中的应用

电化学储能电站普遍采用组态型EMS,通过查看监控画面实现对储能电站电池、BMS、PCS、消防等设备运行状态的监视。提出一种在锂离子电化学储能电站EMS系统中自动巡视监控画面数据的方法,通过周期性自动扫描监控画面上的设备运行数据,识别信号点的数据品质类型,将设备的实时状态数据与健康特征值做对比,主动发现画面上遥测越限、数据不刷新、封锁、遥测遥信不匹配等异常数据,识别异常设备,生成异常数据报告。通过采用这种画面自动巡视技术,可以减轻储能电站监控员的画面监盘工作压力,提高储能电站的运行效率和安全性。

EMS高级应用软件和DTS培训系统在电网运行与调度员培训中的应用

本文主要介绍EMS高级应用软件和DTS培训系统在电网运行与调度员培训中的应用策略。EMS高级应用软件在电网运行中发挥重要作用,具有监测、控制、优化和安全管理等功能。DTS培训系统则满足调度员培训的需求,通过模拟和实践训练提升其应急处理和团队协作能力。在电网运行与调度员培训的应用策略中,安全管理、运行优化、紧急事件处理和团队协作是关键方面。