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Phase–amplitude model for doubly fed induction generators 预览
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作者 Hua HUANG Ping JU +3 位作者 Xueping PAN Yuqing JIN Xiaoming YUAN Yuan GAO 《现代电力系统与清洁能源学报(英文)》 CSCD 2019年第2期369-379,共11页
The doubly fed induction generator(DFIG) is major type of wind turbine generator used in grid-connected wind farms. Practical models of DFIG have been built to study the influence of wind power generation on power sys... The doubly fed induction generator(DFIG) is major type of wind turbine generator used in grid-connected wind farms. Practical models of DFIG have been built to study the influence of wind power generation on power system dynamics. However, most existing practical models of the DFIG are based on rectangular coordinates,in which frequency variation is neglected. In this paper, a phase-amplitude(P-A) model is proposed for a DFIG based on phase and amplitude of the internal voltage. The model structure is much like that of the synchronous generator, and the rotor voltage can manipulate both the amplitude and the phase of the internal voltage.Comparisons have been made between the new P-A model of the DFIG and the synchronous generator model,as well as the asynchronous motor model.The contributions of the new P-A model of the DFIG are discussed and it is demonstrated that the proposed model has better ability in describing power system dynamic phenomena such as voltage dynamics and structural dynamics. Simulation results and a field test validate these contributions. 展开更多
关键词 DOUBLY fed induction generator(DFIG) MODEL Internal VOLTAGE VOLTAGE DYNAMICS Frequency DYNAMICS
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CsWRKY22启动子的克隆及响应柑橘溃疡病菌侵染的表达特征
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作者 王丽娟 龙俊宏 +6 位作者 谢竹 吴柳 彭爱红 何永睿 龙琴 陈善春 邹修平 《园艺学报》 CAS CSCD 北大核心 2019年第4期677-690,共14页
由柑橘黄单胞杆菌致病变种(Xanthomonas citri subsp. citri,Xcc)引起的柑橘溃疡病严重危害着柑橘产业的健康可持续发展。前期研究表明,CsWRKY22可能是溃疡病感病基因。从‘晚锦橙’(Citrus sinensis Osbeck)中克隆了CsWRKY22的两个等... 由柑橘黄单胞杆菌致病变种(Xanthomonas citri subsp. citri,Xcc)引起的柑橘溃疡病严重危害着柑橘产业的健康可持续发展。前期研究表明,CsWRKY22可能是溃疡病感病基因。从‘晚锦橙’(Citrus sinensis Osbeck)中克隆了CsWRKY22的两个等位启动子pCsWRKY22-1和pCsWRKY22-2,长度分别为1 428和1406bp。序列分析表明两个等位启动子序列一致性为91.76%。两个等位启动子含有多种参与植物防御反应和生长发育的顺式作用元件,相同元件的数量和位置基本一致,不同的是,在TATA-box下游,pCsWRKY22-1含有2个22 bp长的TA-rich转录增强序列,而pCsWRKY22-2只含有1个。构建CsWRKY22启动子控制GUS报告基因的植物表达载体pC sW RKY22::GUS,并用农杆菌介导法转化‘晚锦橙’,经GFP活性检测和PCR鉴定获得pCsWRKY22-1::GUS和pCsWRKY22-2::GUS转基因植株各8株和4株。GUS组织化学染色、GUS酶活性及定量PCR分析表明,CsWRKY22启动子具有较强的机械伤诱导活性和柑橘溃疡病病原菌诱导活性,同时具有一定水平的基础表达特性。pCsWRKY22-1机械伤诱导活性高于pCsWRKY22-2,而pCsWRKY22-2溃疡病菌诱导活性高于pCsWRKY22-1。 展开更多
关键词 柑橘溃疡病 CsWRKY22 启动子 诱导 GUS
On C-Bases, Partition Pairs and Filtrations for Induced or Restricted Specht Modules
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作者 Christos A. Pallikaros 《代数集刊:英文版》 SCIE CSCD 2019年第1期161-180,共20页
We obtain alternative explicit Specht filtrations for the induced and the restricted Specht modules in the Hecke algebra of the symmetric group (defined over the ring A = Z[g^1/2, q^-1/2], where q is an indeterminate)... We obtain alternative explicit Specht filtrations for the induced and the restricted Specht modules in the Hecke algebra of the symmetric group (defined over the ring A = Z[g^1/2, q^-1/2], where q is an indeterminate) using C-bases for these modules. Moreover, we provide a link bet ween a certain C-basis for the induced Specht module and the notion of pairs of partitions. 展开更多
关键词 Kazhdan-Lusztig cell Specht FILTRATION induction and RESTRICTION pair of PARTITIONS
分娩球在COOK球囊引产中对分娩结局的影响
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作者 冯英 杨柏财 徐萍 《中华医学杂志》 CAS CSCD 北大核心 2019年第25期1972-1975,共4页
目的探讨分娩球在COOK球囊促宫颈成熟及引产过程中的效果研究。方法选择2017年5月1日至12月31日在嘉兴市妇幼保健院产科住院分娩的患者580例。根据患者意愿,将分娩球+COOK球囊促宫颈成熟290例设为试验组,将COOK球囊促宫颈成熟组290例设... 目的探讨分娩球在COOK球囊促宫颈成熟及引产过程中的效果研究。方法选择2017年5月1日至12月31日在嘉兴市妇幼保健院产科住院分娩的患者580例。根据患者意愿,将分娩球+COOK球囊促宫颈成熟290例设为试验组,将COOK球囊促宫颈成熟组290例设为对照组,比较两组患者Bishop评分改善、产程时间、剖宫产率、产钳助产率、产后出血量及新生儿评分等结局指标。结果(1)两组患者年龄、体质量指数、学历、户籍及妊娠次数间差异无统计学意义(P>0.05);(2)两组患者Bishop评分改善差异无统计学意义(P>0.05);(3)试验组总产程时间为(8.4±1.5)h,对照组为(10.6±2.7)h,差异有统计学意义(P<0.05),试验组和对照组的剖宫产率(11.03%比15.17%)、产钳助产率(5.52%比8.28%)及产后出血量(308 ml±9 ml比367 ml±16 ml)均差异有统计学意义(P<0.05)。结论在COOK球囊引产中应用分娩球可缩短产程时间、降低剖宫产率及产钳助产率,减少产后出血量,具有一定的临床应用价值。 展开更多
关键词 分娩球 COOK球囊 弓I产
欧洲卫矛叶片愈伤组织诱导及培养 预览
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作者 余慧 丁彦芬 +1 位作者 卓启苗 朱贵珍 《东北林业大学学报》 CAS CSCD 北大核心 2019年第5期19-24,共6页
以欧洲卫矛(Euonymus europaea)叶片为外植体,研究不同消毒时间对叶片消毒的影响,不同激素种类及质量浓度对愈伤组织诱导、增殖及分化的影响。结果表明:75%酒精30 s+3%次氯酸钠18 min消毒效果最好,污染率最低,为18.74%。6-BA(6-苄氨基嘌... 以欧洲卫矛(Euonymus europaea)叶片为外植体,研究不同消毒时间对叶片消毒的影响,不同激素种类及质量浓度对愈伤组织诱导、增殖及分化的影响。结果表明:75%酒精30 s+3%次氯酸钠18 min消毒效果最好,污染率最低,为18.74%。6-BA(6-苄氨基嘌呤)对欧洲卫矛叶片愈伤组织诱导的效果好于TDZ(噻苯隆),愈伤组织质量更优。适宜作欧洲卫矛诱导培养基的为MS+1.0 mg·L^-1 6-BA+0.1 mg·L^-1 NAA,出愈率达60.7%。适宜作欧洲卫矛增殖培养基的为MS+2.0 mg·L^-1 6-BA+0.3 mg·L^-1NAA+0.1 mg·L^-1 2,4-D(2,4-二氯苯氧乙酸),增殖率达98.1%,增殖系数达1.953。适宜作欧洲卫矛分化培养基的为MS+1.0 mg·L^-1 6-BA+0.1 mg·L^-1 NAA,分化率达47.1%,分化的芽点多。 展开更多
关键词 欧洲卫矛 叶片愈伤组织 诱导 增殖 分化
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Predictive value of tumor volume reduction rates before and after induction chemotherapy in determining the radiosensitivity and prognosis of locally advanced nasopharyngeal carcinomas 预览
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作者 Yang Song Ge Wang +2 位作者 Chuan Chen Yun Liu Bin Wang 《肿瘤学与转化医学:英文版》 2019年第1期12-18,共7页
Objective This study investigated the predictive value of tumor volume reduction rates (TVRRs) before and after induction chemotherapy in determining the radiosensitivity and prognosis of patients with locally advance... Objective This study investigated the predictive value of tumor volume reduction rates (TVRRs) before and after induction chemotherapy in determining the radiosensitivity and prognosis of patients with locally advanced nasopharyngeal carcinomas (NPCs). Methods The clinical data of 172 patients with locally advanced primary NPCs who were treated from January 2009 to December 2012 were collected. Tumor regression was evaluated based on the results of the computed tomography scan or magnetic resonance imaging studies. Data about the tumor diameters before and after induction chemotherapy and after radiotherapy as well as the survival times of the patients were obtained. Results All 172 patients had NPCs. After radiotherapy, the TVRR in patients without residual tumor cells was higher than that in patients with residual tumor cells after induction chemotherapy (median values: 47.7% and 15.1%, respectively), and the 5-year survival rates were 80.3% and 45.6%, respectively. Neck lymph node metastasis was observed in 161 of 172 patients, and the TVRRs were similar (median values: 46.8% in 161 patients without residual tumor cells and 11.1% in 161 patients with residual tumor cells). The 5-year survival rate of the 161 patients without residual tumor cells was 84.5%, and that of patients with residual tumor cells was 37.3%. As shown by the receiver operating characteristic (ROC) curve, the area under the curve (AUC) of the ROC curve for TVRRs in patients with primary NPCs but without residual tumors was 0.851, whereas that for TVRRs in patients with neck lymph node metastasis but without residual tumors was 0.784. This result indicates that TVRR has a high diagnostic performance. The univariate Cox regression analysis showed that clinical stage, TVRR in primary NPCs, neck lymph node metastatic lesions before and after induction chemotherapy, presence or absence of residual tumor cells in primary NPCs, and neck lymph node metastatic lesions after radiotherapy were significantly correlated to overall survival (OS). Results 展开更多
关键词 NASOPHARYNGEAL CARCINOMAS INDUCTION CHEMOTHERAPY RADIOSENSITIVITY PROGNOSIS
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CB诱导熊本牡蛎三倍体及其存活率与倍化率的变化关系 预览
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作者 武祥伟 张跃环 +3 位作者 肖述 秦艳平 莫日馆 喻子牛 《水产学报》 CAS CSCD 北大核心 2019年第4期1029-1037,共9页
为诱导熊本牡蛎三倍体,研究了细胞松弛素B(CB)浓度、诱导起始时间、诱导持续时间等因素对卵裂率、D幼率、三倍体率的影响,并分析了幼虫、稚贝及成贝的存活率和三倍体率的变化特征。结果显示,CB浓度为0.5~0.6 mg/L,诱导起始时间为40%受... 为诱导熊本牡蛎三倍体,研究了细胞松弛素B(CB)浓度、诱导起始时间、诱导持续时间等因素对卵裂率、D幼率、三倍体率的影响,并分析了幼虫、稚贝及成贝的存活率和三倍体率的变化特征。结果显示,CB浓度为0.5~0.6 mg/L,诱导起始时间为40%受精卵释放第一极体,诱导持续时间为20 min时可获得87%的三倍体率。卵裂率、D幼率、三倍体率的最大影响因素分别为CB浓度、诱导持续时间、诱导起始时间与诱导持续时间。三倍体率与卵裂率无显著负相关性,而与D幼率呈显著正相关。因此,减小CB浓度或诱导持续时间,可同时获得较高的三倍体率与幼虫产量。3~15日龄三倍体组与对照组的存活率分别由71.27%与96.09%降低至34.14%与58.80%,成贝期450日龄(9月)三倍体组与对照组的存活率分别为53.62%与44.67%。3~9日龄三倍体率从87%降低至77%,而90~450日龄三倍体率平均值为59.21%±4.99%,表明幼贝与成贝期三倍体率变化较小,三倍体率的维持与存活率无显著相关性。 展开更多
关键词 熊本牡蛎 三倍体 成活率 细胞松弛素B(CB) 诱导
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粘虫过氧化物酶MsPOD基因的克隆及不同温度胁迫的诱导效应 预览
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作者 杨航 王晓云 +1 位作者 裴海英 樊东 《中国生物防治学报》 CSCD 北大核心 2019年第1期44-52,共9页
过氧化物酶(POD)是昆虫体内一种很关键的抗氧化酶,在维持昆虫体内氧化还原的动态平衡及保护昆虫免受氧化损伤方面起到重要的作用。本试验通过转录组测序方法获得一条粘虫过氧化物酶基因的cDNA序列,该序列命名为MsPOD(GenBank登录号:MH60... 过氧化物酶(POD)是昆虫体内一种很关键的抗氧化酶,在维持昆虫体内氧化还原的动态平衡及保护昆虫免受氧化损伤方面起到重要的作用。本试验通过转录组测序方法获得一条粘虫过氧化物酶基因的cDNA序列,该序列命名为MsPOD(GenBank登录号:MH606240)。该序列全长2433 bp,开放阅读框长度为2061 bp,编码686个氨基酸组成的多肽,分子量约76.1 ku,等电点5.68,具有1个标志性的动物亚铁血红素过氧化物酶细胞粘附蛋白结构域。氨基酸序列比对表明,MsPOD的氨基酸序列与鳞翅目夜蛾科其他昆虫亲缘关系较近,其中与棉铃虫POD氨基酸序列同源性最高,达92%。基因表达水平研究发现,MsPOD基因在不同发育阶段和不同组织中差异表达,在蛹期和唾腺中表达量最高。温度梯度诱导后,MsPOD基因在不同时间点的表达量具有显著差异,经35℃下12h处理后表达量最高。研究结果为进一步研究过氧化物酶在昆虫体内的保护性作用以及利用该基因进行分子设计来防治粘虫奠定理论基础。 展开更多
关键词 粘虫 过氧化物酶 克隆 温度 诱导
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Comparison of transvaginal cervical length and modified Bishop's score as predictors for labor induction in nulliparous women
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作者 El Mekkawi SF Hanafi S +2 位作者 Khalaf-Allah AE Ibrahim A.Abdelazim Mohammed EK 《亚太生殖杂志(英文版)》 2019年第1期34-38,共5页
Objective: To compare the transvaginal cervical length (TVCL) to the modified Bishop's score for prediction of successful labor induction in nulliparous women. Methods: A total of 210 nulliparous women who were di... Objective: To compare the transvaginal cervical length (TVCL) to the modified Bishop's score for prediction of successful labor induction in nulliparous women. Methods: A total of 210 nulliparous women who were diagnosed as premature rupture of membranes were recruited in this comparative prospective study, which was carried out in the Obstetrics and Gynecology Department of Ain Shams University, Egypt over two years for labor induction. The studied women were examined by trans-vaginal ultrasound for measurement of the cervical length (CL) and vaginally to calculate the modified Bishop's score, followed by induction of labor. Collected data were analyzed to compare the TVCL to the modified Bishop's score for prediction of successful labor induction in nulliparous women. The success of induction process was defined as vaginal birth after the induction of labor. Results: One hundred and forty-three women of studied women had CL <28 mm;122 of them delivered vaginally (P=0.030). One hundred and forty-six women of studied women had modified Bishop's score >4;128 of them delivered vaginally (P=0.006). The CL <28 mm was significantly more specific with more positive predictive value as predictor of successful labor induction compared to modified Bishop's score. Induction to delivery time was significantly shorter in women with CL <28 mm than women with CL ≥28 mm (P=0.02;95% confidence interval: 4.9-8.4). In addition, induction to delivery time was significantly shorter in women with Bishop's score >4 than women with Bishop's score of 曑4 (P=0.01;95% confidence interval: 1.6-4.5). Conclusions: Both TVCL and the modified Bishop's score are complementary tools in pre-induction cervical assessment before induction of labor, while the TVCL at <28 mm is significantly more specific with more positive predictive value as predictor of successful induction than the modified Bishop's score. 展开更多
关键词 CERVICAL length LABOR induction MODIFIED Bishop's SCORE
成年火龙果植株茎段愈伤组织诱导、增殖及分化研究 预览
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作者 邓仁菊 范建新 +2 位作者 王永清 刘涛 金吉芬 《西南农业学报》 CSCD 北大核心 2019年第3期595-603,共9页
【目的】为建立和优化火龙果的再生体系。【方法】以成年植株茎段作为外植体,研究了不同表面灭菌方法、不同取样时间及取样部位对外植体污染、褐化的影响,以及不同植物生长调节剂浓度及配比、培养条件等对茎段愈伤组织诱导、增殖及分化... 【目的】为建立和优化火龙果的再生体系。【方法】以成年植株茎段作为外植体,研究了不同表面灭菌方法、不同取样时间及取样部位对外植体污染、褐化的影响,以及不同植物生长调节剂浓度及配比、培养条件等对茎段愈伤组织诱导、增殖及分化的影响。【结果】适宜幼嫩茎段表面灭菌的方式为75%酒精消毒30s+0.1%HgCl2消毒6~8min,适宜成熟茎段表面灭菌的方式为75%酒精消毒30s+0.1%HgCl2消毒12~15min;以春季萌发的10~20cm枝条诱导愈伤组织效果较好,最适愈伤组织诱导的培养基为MS+TDZ0.4mg/L+KT0.8mg/L,暗培养7d,再转入光照培养,愈伤组织为黄绿色、致密状,外表有颗粒状突起。愈伤组织增殖培养基以MS+TDZ0.4mg/L+KT(或ZT)0.8mg/L效果较好,增殖系数在8倍以上。在愈伤组织分化过程中,添加20%~30%的椰子水对不定芽的形成具有一定促进作用,但分化率较低。【结论】以成年火龙果植株茎段建立的再生体系,愈伤组织分化率总体表现较低,最高分化率仅13%,因此还有待进一步加强和完善。 展开更多
关键词 火龙果 茎段 愈伤组织 诱导 增殖 分化
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A Sliding Mode Approach to Enhance the Power Quality of Wind Turbines Under Unbalanced Voltage Conditions 预览
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作者 Mohammad Javad Morshed Afef Fekih 《自动化学报:英文版》 CSCD 2019年第2期566-574,共9页
An integral terminal sliding mode-based control design is proposed in this paper to enhance the power quality of wind turbines under unbalanced voltage conditions. The design combines the robustness, fast response, an... An integral terminal sliding mode-based control design is proposed in this paper to enhance the power quality of wind turbines under unbalanced voltage conditions. The design combines the robustness, fast response, and high quality transient characteristics of the integral terminal sliding mode control with the estimation properties of disturbance observers. The controller gains were auto-tuned using a fuzzy logic approach.The effectiveness of the proposed design was assessed under deep voltage sag conditions and parameter variations. Its dynamic response was also compared to that of a standard SMC approach.The performance analysis and simulation results confirmed the ability of the proposed approach to maintain the active power,currents, DC-link voltage and electromagnetic torque within their acceptable ranges even under the most severe unbalanced voltage conditions. It was also shown to be robust to uncertainties and parameter variations, while effectively mitigating chattering in comparison with the standard SMC. 展开更多
关键词 DOUBLY fed induction generators(DFIG) fuzzy APPROACH integral terminal SLIDING mode control(ITSMC) observer power quality voltage unbalances wind turbines
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Techniques of microwave permeability characterization for thin films
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作者 李喜玲 王建波 柴国志 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第9期37-49,共13页
We review the microwave methods to characterize the material properties, including the established and the emerging techniques in material characterization, especially the permeability spectra of the magnetic thin fil... We review the microwave methods to characterize the material properties, including the established and the emerging techniques in material characterization, especially the permeability spectra of the magnetic thin films.Almost all aspects of the microwave techniques for characterizing the permeability of thin films at microwave frequencies, including the new methods developed by our group, are presented.Firstly, the introduction part is presented.Secondly, the coaxial-line with transmission/reflection methods and the pickup coil with electromagnetic induction method are presented.Thirdly, the most widely used shorted microstrip technique is discussed in detail by the equivalent circuit method, transmission line method,and electromagnetic induction method.Fourthly, the coplanar waveguide method and the near-field probe method are also introduced.Finally, the high temperature permeability characterization by using the shorted microstrip line, the near-field microwave probe, and the shorted microstrip line probe are described in detail.This paper may be useful for researchers or engineers who will build up such measurement fixture to make full use of the existing methods or to develop original methods to meet the requirements for ever-rising measurements. 展开更多
关键词 high frequency PERMEABILITY coaxial-line methods induction COIL METHOD shorted MICROSTRIP technique COPLANAR WAVEGUIDE METHOD
A Long-Range Generalized Predictive Control Algorithm for a DFIG Based Wind Energy System 预览
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作者 J.S.Solis-Chaves Lucas L.Rodrigues +1 位作者 C.M.Rocha-Osorio Alfeu J.Sguarezi Filho 《自动化学报:英文版》 CSCD 2019年第5期1209-1219,共11页
This paper presents a new Long-range generalized predictive controller in the synchronous reference frame for a wind energy system doubly-fed induction generator based. This controller uses the state space equations t... This paper presents a new Long-range generalized predictive controller in the synchronous reference frame for a wind energy system doubly-fed induction generator based. This controller uses the state space equations that consider the rotor current and voltage as state and control variables, to execute the predictive control action. Therefore, the model of the plant must be transformed into two discrete transference functions, by means of an auto-regressive moving average model, in order to attain a discrete and decoupled controller, which makes it possible to treat it as two independent single-input single-output systems instead of a magnetic coupled multiple-input multiple-output system. For achieving that, a direct power control strategy is used, based on the past and future rotor currents and voltages estimation. The algorithm evaluates the rotor current predictors for a defined prediction horizon and computes the new rotor voltages that must be injected to controlling the stator active and reactive powers. To evaluate the controller performance, some simulations were made using Matlab/Simulink. Experimental tests were carried out with a small-scale prototype assuming normal operating conditions with constant and variable wind speed profiles. Finally, some conclusions respect to the dynamic performance of this new controller are summarized. 展开更多
关键词 Direct power CONTROL DOUBLY-FED induction GENERATOR flux oriented CONTROL generalized PREDICTIVE CONTROL LONG-RANGE PREDICTIVE CONTROL wind energy systems
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樟叶越桔愈伤组织诱导及其细胞悬浮培养体系建立 预览
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作者 付羚 张訸 +3 位作者 罗旭璐 尚俊可 唐军荣 赵平 《西部林业科学》 CAS 北大核心 2019年第5期119-124,130共7页
以樟叶越桔组培苗幼嫩叶片为外植体,研究了植物生长调节剂对其愈伤组织诱导和增殖的影响,建立樟叶越桔的细胞悬浮培养体系。结果表明,樟叶越桔的愈伤组织诱导的适宜培养基为WPM+2.0mg/L6-BA+0.05mg/LNAA+2.0mg/L2,4-D+30%蔗糖。樟叶越... 以樟叶越桔组培苗幼嫩叶片为外植体,研究了植物生长调节剂对其愈伤组织诱导和增殖的影响,建立樟叶越桔的细胞悬浮培养体系。结果表明,樟叶越桔的愈伤组织诱导的适宜培养基为WPM+2.0mg/L6-BA+0.05mg/LNAA+2.0mg/L2,4-D+30%蔗糖。樟叶越桔愈伤组织增殖的最佳植物生长调节剂组合为2.0mg/LZT+0.4mg/LNAA,得到的蓬松愈伤组织适宜进行其悬浮培养。WPM3/5有机为适宜的改良培养基,通过细胞悬浮生长曲线的测定,确定樟叶越桔细胞悬浮培养较适宜的继代周期为14d,最长不宜超过21d。 展开更多
关键词 樟叶越桔 愈伤组织 诱导 增殖 细胞悬浮培养
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青稞再生体系的建立及优良受体基因型筛选 预览
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作者 徐齐君 王玉林 +5 位作者 原红军 巴桑玉珍 扎桑 于明寨 杨春葆 尼玛扎西 《大麦与谷类科学》 2019年第4期1-10,38共11页
为了筛选出高频再生能力强的青稞基因型,对青稞成熟胚处理方式、愈伤诱导、胚性愈伤诱导和分化的培养基成分进行了研究。结果表明,碎胚携带胚乳更利于青稞愈伤组织的发生。不同青稞品种在不同培养基上的愈伤诱导情况存在显著差异。供试... 为了筛选出高频再生能力强的青稞基因型,对青稞成熟胚处理方式、愈伤诱导、胚性愈伤诱导和分化的培养基成分进行了研究。结果表明,碎胚携带胚乳更利于青稞愈伤组织的发生。不同青稞品种在不同培养基上的愈伤诱导情况存在显著差异。供试材料中只有青稞昆仑14号、ZYM0439和C1可诱导得到淡黄色、致密的胚性愈伤,且昆仑14号和ZYM0439可获得高频的次级胚性愈伤。由于C1在初生愈伤诱导的时候很容易出芽和水渍化,所以次级胚性愈伤诱导率较低。在不同的分化培养基上,青稞ZYM0439的分化能力明显优于青稞昆仑14号,更适宜用作青稞遗传转化研究的材料。 展开更多
关键词 青稞 成熟胚 愈伤组织 诱导 植株再生
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水稻抗性蛋白OsRRK1的诱导
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作者 马银花 易松望 +2 位作者 何雨航 谭显胜 金晨钟 《华中昆虫研究》 2019年第1期269-273,共5页
水稻基因OsRRK1(Rop-interacting receptor-like kinase 1)过量表达以后对褐飞虱的抗性增强,并且抗性程度与OsRRK1基因的表达量有关,转录组数据结果表明这个过程可能是通过激酶级联信号传递,也可能是通过转录因子调控。进一步了解具体... 水稻基因OsRRK1(Rop-interacting receptor-like kinase 1)过量表达以后对褐飞虱的抗性增强,并且抗性程度与OsRRK1基因的表达量有关,转录组数据结果表明这个过程可能是通过激酶级联信号传递,也可能是通过转录因子调控。进一步了解具体抗性机理,还需要诱导和纯化出OsRRK1蛋白,然后对蛋白做进一步分析。 展开更多
关键词 水稻 OsRRK1 抗性 诱导
双球囊导管在瘢痕子宫足月妊娠中的应用 预览
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作者 孙瑞清 郑剑兰 +3 位作者 刘景兮 张小琼 汪文雁 陈琼 《发育医学电子杂志》 2019年第3期208-213,共6页
目的 探讨双球囊导管在瘢痕子宫足月妊娠引产中的安全性和有效性。方法 选取2016年10月至2018年3月在厦门大学附属成功医院产科产检及分娩,且符合纳入标准的孕产妇为研究对象,将既往有1次子宫下段剖宫产史且无阴道试产禁忌证的57例宫颈... 目的 探讨双球囊导管在瘢痕子宫足月妊娠引产中的安全性和有效性。方法 选取2016年10月至2018年3月在厦门大学附属成功医院产科产检及分娩,且符合纳入标准的孕产妇为研究对象,将既往有1次子宫下段剖宫产史且无阴道试产禁忌证的57例宫颈未成熟的足月孕产妇设为瘢痕组,另外随机选取同期57例非瘢痕子宫、宫颈未成熟的足月妊娠孕产妇设为非瘢痕组。两组均用双球囊导管促宫颈成熟及引产,比较两组间的分娩方式、手术指征、引产前与引产后宫颈Bishop评分、引产时间、产程时间、产后24h的出血量、新生儿出生体质量、新生儿窒息和子宫破裂等,并分析引产后剖宫产的影响因素。采用t检验、χ2检验或Fisher确切概率法、Logistic回归分析法进行统计分析。结果 两组孕产妇引产前与引产后宫颈Bishop评分、引产时间及总产程比较差异无统计学意义(P>0.05);瘢痕组的年龄较非瘢痕组大,差异有统计学意义[(33.8±4.0)与(30.2±4.2)岁,t=-4.722,P<0.05]。瘢痕组阴道分娩率为71.9%,非瘢痕组为78.9%,两组比较差异无统计学意义(P>0.05)。两组手术指征比较,差异无统计学意义(P>0.05)。两组的产后24h出血量、新生儿出生体质量比较,差异无统计学意义(P>0.05)。Logistic回归分析表明引产后宫颈Bishop评分高是剖宫产的保护因素(OR=0.426,95%CI为0.234~0.765,P=0.005),新生儿出生体质量大是剖宫产的危险因素(OR=1.001,95%CI为1.001~1.004,P=0.033),孕产妇年龄、孕周以及瘢痕子宫不是引产后剖宫产的危险因素。结论 双球囊导管可用于瘢痕子宫足月妊娠孕产妇的促宫颈成熟及引产,降低再次剖宫产率,同时不增加母婴不良结局。 展开更多
关键词 瘢痕子宫 双球囊导管 引产 剖宫产
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Effects of Ginkgo biloba extract EGb761 on neural differentiation of stem cells offer new hope for neurological disease treatment 预览
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作者 Chao Ren Yong-Qiang Ji +5 位作者 Hong Liu Zhe Wang Jia-Hui Wang Cai-Yi Zhang Li-Na Guan Pei-Yuan Yin 《中国神经再生研究:英文版》 SCIE CAS CSCD 2019年第7期1152-1157,共6页
Stem cell transplantation has brought new hope for the treatment of neurological diseases.The key to stem cell therapy lies in inducing the specific differentiation of stem cells into nerve cells.Because the different... Stem cell transplantation has brought new hope for the treatment of neurological diseases.The key to stem cell therapy lies in inducing the specific differentiation of stem cells into nerve cells.Because the differentiation of stem cells in vitro and in vivo is affected by multiple factors,the final differentiation outcome is strongly associated with the microenvironment in which the stem cells are located.Accordingly,the optimal microenvironment for inducing stem cell differentiation is a hot topic.EGb761 is extracted from the leaves of the Ginkgo biloba tree.It is used worldwide and is becoming one of the focuses of stem cell research.Studies have shown that EGb761 can antagonize oxygen free radicals,stabilize cell membranes,promote neurogenesis and synaptogenesis,increase the level of brain-derived neurotrophic factors,and replicate the environment required during the differentiation of stem cells into nerve cells.This offers the possibility of using EGb761 to induce the differentiation of stem cells,facilitating stem cell transplantation.To provide a comprehensive reference for the future application of EGb761 in stem cell therapy,we reviewed studies investigating the influence of EGb761 on stem cells.These started with the composition and neuropharmacology of EGb761,and eventually led to the finding that EGb761 and some of its important components play important roles in the differentiation of stem cells and the protection of a beneficial microenvironment for stem cell transplantation. 展开更多
关键词 nerve REGENERATION GINKGO biloba extract GINKGOLIDE B traditional Chinese medicine STEM cells induction of differentiation STEM cell transplantation synaptic plasticity pharmacological effect NEUROLOGICAL diseases nervous systems neural REGENERATION
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论惠威尔对培根归纳思想的继承与发展 预览
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作者 孟令芳 《科学.经济.社会》 2019年第2期36-41,48共7页
培根是古典归纳逻辑的开拓者,他坚持逐渐且连续的归纳,认为从特殊事实到普遍真理是一个循序渐进的推理过程。惠威尔继承并革新了培根的归纳思想,具体来说,惠威尔从科学史观、归纳过程中推理形式多样性、归纳法能够产生理论科学等方面继... 培根是古典归纳逻辑的开拓者,他坚持逐渐且连续的归纳,认为从特殊事实到普遍真理是一个循序渐进的推理过程。惠威尔继承并革新了培根的归纳思想,具体来说,惠威尔从科学史观、归纳过程中推理形式多样性、归纳法能够产生理论科学等方面继承了培根的归纳思想,他的归纳表就是最好的说明;所谓革新,即用基本对立的认识论代替了培根的极端经验主义认识论,惠威尔认为理性和经验同样重要,强调概念这一理性因素在科学知识中的作用,进而否定了培根的机械的发现方法。事实上,基本对立认识论的思想主旨早在培根的作品中就有所萌芽,因此说惠威尔对培根的革新是一种继承基础上的丰富和发展而非绝对的否定。和培根一样,惠威尔也是归纳逻辑的代表。 展开更多
关键词 培根 惠威尔 归纳 对立的认识论 概念
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仙茅愈伤组织诱导和细胞悬浮培养体系的建立
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作者 邹璐 何钢 +3 位作者 刘贤桂 张虹 席飞飞 叶生宝 《分子植物育种》 CAS CSCD 北大核心 2019年第16期5383-5389,共7页
为初步建立仙茅(Curculigo orchiodes Gaertn)细胞悬浮培养体系。以仙茅幼叶为外植体,诱导产生愈伤组织后进行仙茅细胞悬浮培养研究。以MS为基本培养基,研究了植物生长调节剂对仙茅愈伤组织诱导和继代的影响,以及接种量,2,4-二氯苯氧乙... 为初步建立仙茅(Curculigo orchiodes Gaertn)细胞悬浮培养体系。以仙茅幼叶为外植体,诱导产生愈伤组织后进行仙茅细胞悬浮培养研究。以MS为基本培养基,研究了植物生长调节剂对仙茅愈伤组织诱导和继代的影响,以及接种量,2,4-二氯苯氧乙酸(2,4-D),蔗糖,水解酪蛋白,2-氮吗啉乙烷磺酸(MES),L-脯氨酸(L-Pro)对仙茅细胞悬浮培养的影响。结果表明:仙茅愈伤组织诱导的最佳培养基为MS+6-BA 1.5 mg/L+NAA 0.5 mg/L,所得的愈伤组织颜色淡黄,质地疏松,诱导率达100%;最佳继代培养基为MS+6-BA 2.0 mg/L+NAA 0.5 mg/L,平均增殖倍数达10.8。仙茅细胞悬浮培养最佳培养基和培养条件为MS+2,4-D 0.5 mg/L+6-BA2.0 mg/L+NAA 0.5 mg/L+蔗糖20 g/L,接种量75 g/L,水解酪蛋白300 mg/L,MES 2 g/L,L-Pro 700 mg/L,摇床转速120 r/min,25℃光照培养,光照时间12 h/d,光照强度1 200 lx。该条件下悬浮细胞生长良好,最大生长量为(9.68±0.2)×10^5个/mL。初步选择出仙茅愈伤组织细胞的悬浮培养条件,也为仙茅细胞扩大培养及有效成分的提取提供物质基础。 展开更多
关键词 仙茅(Curculigo orchiodes Gaertn) 愈伤组织 诱导 悬浮培养
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